<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/sys.c, branch v2.6.32.52</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>sched: Remove USER_SCHED</title>
<updated>2011-02-17T23:37:19+00:00</updated>
<author>
<name>Dhaval Giani</name>
<email>dhaval.giani@gmail.com</email>
</author>
<published>2011-02-10T08:48:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b271aebc0a8e8e75c8f32cd0a9a41a0b8a6166e8'/>
<id>b271aebc0a8e8e75c8f32cd0a9a41a0b8a6166e8</id>
<content type='text'>
Commit: 7c9414385ebfdd87cc542d4e7e3bb0dbb2d3ce25 upstream

Remove the USER_SCHED feature. It has been scheduled to be removed in
2.6.34 as per http://marc.info/?l=linux-kernel&amp;m=125728479022976&amp;w=2

[trace from referenced thread]
[1046577.884289] general protection fault: 0000 [#1] SMP
[1046577.911332] last sysfs file: /sys/devices/platform/coretemp.7/temp1_input
[1046577.938715] CPU 3
[1046577.965814] Modules linked in: ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables coretemp k8temp
[1046577.994456] Pid: 38, comm: events/3 Not tainted 2.6.32.27intel #1 X8DT3
[1046578.023166] RIP: 0010:[] [] sched_destroy_group+0x3c/0x10d
[1046578.052639] RSP: 0000:ffff88043e5abe10 EFLAGS: 00010097
[1046578.081360] RAX: ffff880139fa5540 RBX: ffff8803d18419c0 RCX: ffff8801d2f8fb78
[1046578.109903] RDX: dead000000200200 RSI: 0000000000000000 RDI: 0000000000000000
[1046578.109905] RBP: 0000000000000246 R08: 0000000000000020 R09: ffffffff816339b8
[1046578.109907] R10: 0000000004e6e5f0 R11: 0000000000000006 R12: ffffffff816339b8
[1046578.109909] R13: ffff8803d63ac4e0 R14: ffff88043e582340 R15: ffffffff8104a216
[1046578.109911] FS: 0000000000000000(0000) GS:ffff880028260000(0000) knlGS:0000000000000000
[1046578.109914] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[1046578.109915] CR2: 00007f55ab220000 CR3: 00000001e5797000 CR4: 00000000000006e0
[1046578.109917] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1046578.109919] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[1046578.109922] Process events/3 (pid: 38, threadinfo ffff88043e5aa000, task ffff88043e582340)
[1046578.109923] Stack:
[1046578.109924] ffff8803d63ac498 ffff8803d63ac4d8 ffff8803d63ac440 ffffffff8104a2c3
[1046578.109927] &lt;0&gt; ffff88043e5abef8 ffff880028276040 ffff8803d63ac4d8 ffffffff81050395
[1046578.109929] &lt;0&gt; ffff88043e582340 ffff88043e5826c8 ffff88043e582340 ffff88043e5abfd8
[1046578.109932] Call Trace:
[1046578.109938] [] ? cleanup_user_struct+0xad/0xcc
[1046578.109942] [] ? worker_thread+0x148/0x1d4
[1046578.109946] [] ? autoremove_wake_function+0x0/0x2e
[1046578.109948] [] ? worker_thread+0x0/0x1d4
[1046578.109951] [] ? kthread+0x79/0x81
[1046578.109955] [] ? child_rip+0xa/0x20
[1046578.109957] [] ? kthread+0x0/0x81
[1046578.109959] [] ? child_rip+0x0/0x20
[1046578.109961] Code: 3c 00 4c 8b 25 02 98 3d 00 48 89 c5 83 cf ff eb 5c 48 8b 43 10 48 63 f7 48 8b 04 f0 48 8b 90 80 00 00 00 48 8b 48 78 48 89 51 08 &lt;48&gt; 89 0a 48 b9 00 02 20 00 00 00 ad de 48 89 88 80 00 00 00 48
[1046578.109975] RIP [] sched_destroy_group+0x3c/0x10d
[1046578.109979] RSP
[1046578.109981] ---[ end trace 5ebc2944b7872d4a ]---

Signed-off-by: Dhaval Giani &lt;dhaval.giani@gmail.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
LKML-Reference: &lt;1263990378.24844.3.camel@localhost&gt;
LKML-Reference: http://marc.info/?l=linux-kernel&amp;m=129466345327931
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Mike Galbraith &lt;efault@gmx.de&gt;
Acked-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit: 7c9414385ebfdd87cc542d4e7e3bb0dbb2d3ce25 upstream

Remove the USER_SCHED feature. It has been scheduled to be removed in
2.6.34 as per http://marc.info/?l=linux-kernel&amp;m=125728479022976&amp;w=2

[trace from referenced thread]
[1046577.884289] general protection fault: 0000 [#1] SMP
[1046577.911332] last sysfs file: /sys/devices/platform/coretemp.7/temp1_input
[1046577.938715] CPU 3
[1046577.965814] Modules linked in: ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables coretemp k8temp
[1046577.994456] Pid: 38, comm: events/3 Not tainted 2.6.32.27intel #1 X8DT3
[1046578.023166] RIP: 0010:[] [] sched_destroy_group+0x3c/0x10d
[1046578.052639] RSP: 0000:ffff88043e5abe10 EFLAGS: 00010097
[1046578.081360] RAX: ffff880139fa5540 RBX: ffff8803d18419c0 RCX: ffff8801d2f8fb78
[1046578.109903] RDX: dead000000200200 RSI: 0000000000000000 RDI: 0000000000000000
[1046578.109905] RBP: 0000000000000246 R08: 0000000000000020 R09: ffffffff816339b8
[1046578.109907] R10: 0000000004e6e5f0 R11: 0000000000000006 R12: ffffffff816339b8
[1046578.109909] R13: ffff8803d63ac4e0 R14: ffff88043e582340 R15: ffffffff8104a216
[1046578.109911] FS: 0000000000000000(0000) GS:ffff880028260000(0000) knlGS:0000000000000000
[1046578.109914] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[1046578.109915] CR2: 00007f55ab220000 CR3: 00000001e5797000 CR4: 00000000000006e0
[1046578.109917] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1046578.109919] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[1046578.109922] Process events/3 (pid: 38, threadinfo ffff88043e5aa000, task ffff88043e582340)
[1046578.109923] Stack:
[1046578.109924] ffff8803d63ac498 ffff8803d63ac4d8 ffff8803d63ac440 ffffffff8104a2c3
[1046578.109927] &lt;0&gt; ffff88043e5abef8 ffff880028276040 ffff8803d63ac4d8 ffffffff81050395
[1046578.109929] &lt;0&gt; ffff88043e582340 ffff88043e5826c8 ffff88043e582340 ffff88043e5abfd8
[1046578.109932] Call Trace:
[1046578.109938] [] ? cleanup_user_struct+0xad/0xcc
[1046578.109942] [] ? worker_thread+0x148/0x1d4
[1046578.109946] [] ? autoremove_wake_function+0x0/0x2e
[1046578.109948] [] ? worker_thread+0x0/0x1d4
[1046578.109951] [] ? kthread+0x79/0x81
[1046578.109955] [] ? child_rip+0xa/0x20
[1046578.109957] [] ? kthread+0x0/0x81
[1046578.109959] [] ? child_rip+0x0/0x20
[1046578.109961] Code: 3c 00 4c 8b 25 02 98 3d 00 48 89 c5 83 cf ff eb 5c 48 8b 43 10 48 63 f7 48 8b 04 f0 48 8b 90 80 00 00 00 48 8b 48 78 48 89 51 08 &lt;48&gt; 89 0a 48 b9 00 02 20 00 00 00 ad de 48 89 88 80 00 00 00 48
[1046578.109975] RIP [] sched_destroy_group+0x3c/0x10d
[1046578.109979] RSP
[1046578.109981] ---[ end trace 5ebc2944b7872d4a ]---

Signed-off-by: Dhaval Giani &lt;dhaval.giani@gmail.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
LKML-Reference: &lt;1263990378.24844.3.camel@localhost&gt;
LKML-Reference: http://marc.info/?l=linux-kernel&amp;m=129466345327931
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Mike Galbraith &lt;efault@gmx.de&gt;
Acked-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pid: make setpgid() system call use RCU read-side critical section</title>
<updated>2010-09-27T00:21:25+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2010-09-01T00:00:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6b7b329a3112648aa31e2d05db61f9bfd4a9b0b6'/>
<id>6b7b329a3112648aa31e2d05db61f9bfd4a9b0b6</id>
<content type='text'>
commit 950eaaca681c44aab87a46225c9e44f902c080aa upstream.

[   23.584719]
[   23.584720] ===================================================
[   23.585059] [ INFO: suspicious rcu_dereference_check() usage. ]
[   23.585176] ---------------------------------------------------
[   23.585176] kernel/pid.c:419 invoked rcu_dereference_check() without protection!
[   23.585176]
[   23.585176] other info that might help us debug this:
[   23.585176]
[   23.585176]
[   23.585176] rcu_scheduler_active = 1, debug_locks = 1
[   23.585176] 1 lock held by rc.sysinit/728:
[   23.585176]  #0:  (tasklist_lock){.+.+..}, at: [&lt;ffffffff8104771f&gt;] sys_setpgid+0x5f/0x193
[   23.585176]
[   23.585176] stack backtrace:
[   23.585176] Pid: 728, comm: rc.sysinit Not tainted 2.6.36-rc2 #2
[   23.585176] Call Trace:
[   23.585176]  [&lt;ffffffff8105b436&gt;] lockdep_rcu_dereference+0x99/0xa2
[   23.585176]  [&lt;ffffffff8104c324&gt;] find_task_by_pid_ns+0x50/0x6a
[   23.585176]  [&lt;ffffffff8104c35b&gt;] find_task_by_vpid+0x1d/0x1f
[   23.585176]  [&lt;ffffffff81047727&gt;] sys_setpgid+0x67/0x193
[   23.585176]  [&lt;ffffffff810029eb&gt;] system_call_fastpath+0x16/0x1b
[   24.959669] type=1400 audit(1282938522.956:4): avc:  denied  { module_request } for  pid=766 comm="hwclock" kmod="char-major-10-135" scontext=system_u:system_r:hwclock_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclas

It turns out that the setpgid() system call fails to enter an RCU
read-side critical section before doing a PID-to-task_struct translation.
This commit therefore does rcu_read_lock() before the translation, and
also does rcu_read_unlock() after the last use of the returned pointer.

Reported-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 950eaaca681c44aab87a46225c9e44f902c080aa upstream.

[   23.584719]
[   23.584720] ===================================================
[   23.585059] [ INFO: suspicious rcu_dereference_check() usage. ]
[   23.585176] ---------------------------------------------------
[   23.585176] kernel/pid.c:419 invoked rcu_dereference_check() without protection!
[   23.585176]
[   23.585176] other info that might help us debug this:
[   23.585176]
[   23.585176]
[   23.585176] rcu_scheduler_active = 1, debug_locks = 1
[   23.585176] 1 lock held by rc.sysinit/728:
[   23.585176]  #0:  (tasklist_lock){.+.+..}, at: [&lt;ffffffff8104771f&gt;] sys_setpgid+0x5f/0x193
[   23.585176]
[   23.585176] stack backtrace:
[   23.585176] Pid: 728, comm: rc.sysinit Not tainted 2.6.36-rc2 #2
[   23.585176] Call Trace:
[   23.585176]  [&lt;ffffffff8105b436&gt;] lockdep_rcu_dereference+0x99/0xa2
[   23.585176]  [&lt;ffffffff8104c324&gt;] find_task_by_pid_ns+0x50/0x6a
[   23.585176]  [&lt;ffffffff8104c35b&gt;] find_task_by_vpid+0x1d/0x1f
[   23.585176]  [&lt;ffffffff81047727&gt;] sys_setpgid+0x67/0x193
[   23.585176]  [&lt;ffffffff810029eb&gt;] system_call_fastpath+0x16/0x1b
[   24.959669] type=1400 audit(1282938522.956:4): avc:  denied  { module_request } for  pid=766 comm="hwclock" kmod="char-major-10-135" scontext=system_u:system_r:hwclock_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclas

It turns out that the setpgid() system call fails to enter an RCU
read-side critical section before doing a PID-to-task_struct translation.
This commit therefore does rcu_read_lock() before the translation, and
also does rcu_read_unlock() after the last use of the returned pointer.

Reported-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sched, cputime: Introduce thread_group_times()</title>
<updated>2010-08-13T20:20:14+00:00</updated>
<author>
<name>Hidetoshi Seto</name>
<email>seto.hidetoshi@jp.fujitsu.com</email>
</author>
<published>2009-12-02T08:28:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=19eb722b762e235458d912fa6621590fa9bd49ed'/>
<id>19eb722b762e235458d912fa6621590fa9bd49ed</id>
<content type='text'>
commit 0cf55e1ec08bb5a22e068309e2d8ba1180ab4239 upstream.

This is a real fix for problem of utime/stime values decreasing
described in the thread:

   http://lkml.org/lkml/2009/11/3/522

Now cputime is accounted in the following way:

 - {u,s}time in task_struct are increased every time when the thread
   is interrupted by a tick (timer interrupt).

 - When a thread exits, its {u,s}time are added to signal-&gt;{u,s}time,
   after adjusted by task_times().

 - When all threads in a thread_group exits, accumulated {u,s}time
   (and also c{u,s}time) in signal struct are added to c{u,s}time
   in signal struct of the group's parent.

So {u,s}time in task struct are "raw" tick count, while
{u,s}time and c{u,s}time in signal struct are "adjusted" values.

And accounted values are used by:

 - task_times(), to get cputime of a thread:
   This function returns adjusted values that originates from raw
   {u,s}time and scaled by sum_exec_runtime that accounted by CFS.

 - thread_group_cputime(), to get cputime of a thread group:
   This function returns sum of all {u,s}time of living threads in
   the group, plus {u,s}time in the signal struct that is sum of
   adjusted cputimes of all exited threads belonged to the group.

The problem is the return value of thread_group_cputime(),
because it is mixed sum of "raw" value and "adjusted" value:

  group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time)

This misbehavior can break {u,s}time monotonicity.
Assume that if there is a thread that have raw values greater
than adjusted values (e.g. interrupted by 1000Hz ticks 50 times
but only runs 45ms) and if it exits, cputime will decrease (e.g.
-5ms).

To fix this, we could do:

  group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time)

But task_times() contains hard divisions, so applying it for
every thread should be avoided.

This patch fixes the above problem in the following way:

 - Modify thread's exit (= __exit_signal()) not to use task_times().
   It means {u,s}time in signal struct accumulates raw values instead
   of adjusted values.  As the result it makes thread_group_cputime()
   to return pure sum of "raw" values.

 - Introduce a new function thread_group_times(*task, *utime, *stime)
   that converts "raw" values of thread_group_cputime() to "adjusted"
   values, in same calculation procedure as task_times().

 - Modify group's exit (= wait_task_zombie()) to use this introduced
   thread_group_times().  It make c{u,s}time in signal struct to
   have adjusted values like before this patch.

 - Replace some thread_group_cputime() by thread_group_times().
   This replacements are only applied where conveys the "adjusted"
   cputime to users, and where already uses task_times() near by it.
   (i.e. sys_times(), getrusage(), and /proc/&lt;PID&gt;/stat.)

This patch have a positive side effect:

 - Before this patch, if a group contains many short-life threads
   (e.g. runs 0.9ms and not interrupted by ticks), the group's
   cputime could be invisible since thread's cputime was accumulated
   after adjusted: imagine adjustment function as adj(ticks, runtime),
     {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0.
   After this patch it will not happen because the adjustment is
   applied after accumulated.

v2:
 - remove if()s, put new variables into signal_struct.

Signed-off-by: Hidetoshi Seto &lt;seto.hidetoshi@jp.fujitsu.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Spencer Candland &lt;spencer@bluehost.com&gt;
Cc: Americo Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Balbir Singh &lt;balbir@in.ibm.com&gt;
Cc: Stanislaw Gruszka &lt;sgruszka@redhat.com&gt;
LKML-Reference: &lt;4B162517.8040909@jp.fujitsu.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0cf55e1ec08bb5a22e068309e2d8ba1180ab4239 upstream.

This is a real fix for problem of utime/stime values decreasing
described in the thread:

   http://lkml.org/lkml/2009/11/3/522

Now cputime is accounted in the following way:

 - {u,s}time in task_struct are increased every time when the thread
   is interrupted by a tick (timer interrupt).

 - When a thread exits, its {u,s}time are added to signal-&gt;{u,s}time,
   after adjusted by task_times().

 - When all threads in a thread_group exits, accumulated {u,s}time
   (and also c{u,s}time) in signal struct are added to c{u,s}time
   in signal struct of the group's parent.

So {u,s}time in task struct are "raw" tick count, while
{u,s}time and c{u,s}time in signal struct are "adjusted" values.

And accounted values are used by:

 - task_times(), to get cputime of a thread:
   This function returns adjusted values that originates from raw
   {u,s}time and scaled by sum_exec_runtime that accounted by CFS.

 - thread_group_cputime(), to get cputime of a thread group:
   This function returns sum of all {u,s}time of living threads in
   the group, plus {u,s}time in the signal struct that is sum of
   adjusted cputimes of all exited threads belonged to the group.

The problem is the return value of thread_group_cputime(),
because it is mixed sum of "raw" value and "adjusted" value:

  group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time)

This misbehavior can break {u,s}time monotonicity.
Assume that if there is a thread that have raw values greater
than adjusted values (e.g. interrupted by 1000Hz ticks 50 times
but only runs 45ms) and if it exits, cputime will decrease (e.g.
-5ms).

To fix this, we could do:

  group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time)

But task_times() contains hard divisions, so applying it for
every thread should be avoided.

This patch fixes the above problem in the following way:

 - Modify thread's exit (= __exit_signal()) not to use task_times().
   It means {u,s}time in signal struct accumulates raw values instead
   of adjusted values.  As the result it makes thread_group_cputime()
   to return pure sum of "raw" values.

 - Introduce a new function thread_group_times(*task, *utime, *stime)
   that converts "raw" values of thread_group_cputime() to "adjusted"
   values, in same calculation procedure as task_times().

 - Modify group's exit (= wait_task_zombie()) to use this introduced
   thread_group_times().  It make c{u,s}time in signal struct to
   have adjusted values like before this patch.

 - Replace some thread_group_cputime() by thread_group_times().
   This replacements are only applied where conveys the "adjusted"
   cputime to users, and where already uses task_times() near by it.
   (i.e. sys_times(), getrusage(), and /proc/&lt;PID&gt;/stat.)

This patch have a positive side effect:

 - Before this patch, if a group contains many short-life threads
   (e.g. runs 0.9ms and not interrupted by ticks), the group's
   cputime could be invisible since thread's cputime was accumulated
   after adjusted: imagine adjustment function as adj(ticks, runtime),
     {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0.
   After this patch it will not happen because the adjustment is
   applied after accumulated.

v2:
 - remove if()s, put new variables into signal_struct.

Signed-off-by: Hidetoshi Seto &lt;seto.hidetoshi@jp.fujitsu.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Spencer Candland &lt;spencer@bluehost.com&gt;
Cc: Americo Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Balbir Singh &lt;balbir@in.ibm.com&gt;
Cc: Stanislaw Gruszka &lt;sgruszka@redhat.com&gt;
LKML-Reference: &lt;4B162517.8040909@jp.fujitsu.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6</title>
<updated>2009-10-29T15:20:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-10-29T15:20:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3242f9804ba992c867360e2b57efc268b8e4e175'/>
<id>3242f9804ba992c867360e2b57efc268b8e4e175</id>
<content type='text'>
* 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
  HWPOISON: fix invalid page count in printk output
  HWPOISON: Allow schedule_on_each_cpu() from keventd
  HWPOISON: fix/proc/meminfo alignment
  HWPOISON: fix oops on ksm pages
  HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page
  HWPOISON: return early on non-LRU pages
  HWPOISON: Add brief hwpoison description to Documentation
  HWPOISON: Clean up PR_MCE_KILL interface
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
  HWPOISON: fix invalid page count in printk output
  HWPOISON: Allow schedule_on_each_cpu() from keventd
  HWPOISON: fix/proc/meminfo alignment
  HWPOISON: fix oops on ksm pages
  HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page
  HWPOISON: return early on non-LRU pages
  HWPOISON: Add brief hwpoison description to Documentation
  HWPOISON: Clean up PR_MCE_KILL interface
</pre>
</div>
</content>
</entry>
<entry>
<title>connector: fix regression introduced by sid connector</title>
<updated>2009-10-29T14:39:25+00:00</updated>
<author>
<name>Christian Borntraeger</name>
<email>borntraeger@de.ibm.com</email>
</author>
<published>2009-10-26T23:49:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0d0df599f1f11f12d589318bacb59a50fb5c0310'/>
<id>0d0df599f1f11f12d589318bacb59a50fb5c0310</id>
<content type='text'>
Since commit 02b51df1b07b4e9ca823c89284e704cadb323cd1 (proc connector: add
event for process becoming session leader) we have the following warning:

Badness at kernel/softirq.c:143
[...]
Krnl PSW : 0404c00180000000 00000000001481d4 (local_bh_enable+0xb0/0xe0)
[...]
Call Trace:
([&lt;000000013fe04100&gt;] 0x13fe04100)
 [&lt;000000000048a946&gt;] sk_filter+0x9a/0xd0
 [&lt;000000000049d938&gt;] netlink_broadcast+0x2c0/0x53c
 [&lt;00000000003ba9ae&gt;] cn_netlink_send+0x272/0x2b0
 [&lt;00000000003baef0&gt;] proc_sid_connector+0xc4/0xd4
 [&lt;0000000000142604&gt;] __set_special_pids+0x58/0x90
 [&lt;0000000000159938&gt;] sys_setsid+0xb4/0xd8
 [&lt;00000000001187fe&gt;] sysc_noemu+0x10/0x16
 [&lt;00000041616cb266&gt;] 0x41616cb266

The warning is
---&gt;    WARN_ON_ONCE(in_irq() || irqs_disabled());

The network code must not be called with disabled interrupts but
sys_setsid holds the tasklist_lock with spinlock_irq while calling the
connector.

After a discussion we agreed that we can move proc_sid_connector from
__set_special_pids to sys_setsid.

We also agreed that it is sufficient to change the check from
task_session(curr) != pid into err &gt; 0, since if we don't change the
session, this means we were already the leader and return -EPERM.

One last thing:
There is also daemonize(), and some people might want to get a
notification in that case. Since daemonize() is only needed if a user
space does kernel_thread this does not look important (and there seems
to be no consensus if this connector should be called in daemonize). If
we really want this, we can add proc_sid_connector to daemonize() in an
additional patch (Scott?)

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Scott James Remnant &lt;scott@ubuntu.com&gt;
Cc: Matt Helsley &lt;matthltc@us.ibm.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Acked-by: Evgeniy Polyakov &lt;zbr@ioremap.net&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit 02b51df1b07b4e9ca823c89284e704cadb323cd1 (proc connector: add
event for process becoming session leader) we have the following warning:

Badness at kernel/softirq.c:143
[...]
Krnl PSW : 0404c00180000000 00000000001481d4 (local_bh_enable+0xb0/0xe0)
[...]
Call Trace:
([&lt;000000013fe04100&gt;] 0x13fe04100)
 [&lt;000000000048a946&gt;] sk_filter+0x9a/0xd0
 [&lt;000000000049d938&gt;] netlink_broadcast+0x2c0/0x53c
 [&lt;00000000003ba9ae&gt;] cn_netlink_send+0x272/0x2b0
 [&lt;00000000003baef0&gt;] proc_sid_connector+0xc4/0xd4
 [&lt;0000000000142604&gt;] __set_special_pids+0x58/0x90
 [&lt;0000000000159938&gt;] sys_setsid+0xb4/0xd8
 [&lt;00000000001187fe&gt;] sysc_noemu+0x10/0x16
 [&lt;00000041616cb266&gt;] 0x41616cb266

The warning is
---&gt;    WARN_ON_ONCE(in_irq() || irqs_disabled());

The network code must not be called with disabled interrupts but
sys_setsid holds the tasklist_lock with spinlock_irq while calling the
connector.

After a discussion we agreed that we can move proc_sid_connector from
__set_special_pids to sys_setsid.

We also agreed that it is sufficient to change the check from
task_session(curr) != pid into err &gt; 0, since if we don't change the
session, this means we were already the leader and return -EPERM.

One last thing:
There is also daemonize(), and some people might want to get a
notification in that case. Since daemonize() is only needed if a user
space does kernel_thread this does not look important (and there seems
to be no consensus if this connector should be called in daemonize). If
we really want this, we can add proc_sid_connector to daemonize() in an
additional patch (Scott?)

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Scott James Remnant &lt;scott@ubuntu.com&gt;
Cc: Matt Helsley &lt;matthltc@us.ibm.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Acked-by: Evgeniy Polyakov &lt;zbr@ioremap.net&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>HWPOISON: Clean up PR_MCE_KILL interface</title>
<updated>2009-10-04T01:23:17+00:00</updated>
<author>
<name>Andi Kleen</name>
<email>ak@linux.intel.com</email>
</author>
<published>2009-10-04T00:20:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1087e9b4ff708976499b4de541d9e1d57d49b60a'/>
<id>1087e9b4ff708976499b4de541d9e1d57d49b60a</id>
<content type='text'>
While writing the manpage I noticed some shortcomings in the
current interface.

- Define symbolic names for all the different values
- Boundary check the kill mode values
- For symmetry add a get interface too. This allows library
code to get/set the current state.
- For consistency define a PR_MCE_KILL_DEFAULT value

Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While writing the manpage I noticed some shortcomings in the
current interface.

- Define symbolic names for all the different values
- Boundary check the kill mode values
- For symmetry add a get interface too. This allows library
code to get/set the current state.
- For consistency define a PR_MCE_KILL_DEFAULT value

Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6</title>
<updated>2009-09-24T14:53:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-09-24T14:53:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=db16826367fefcb0ddb93d76b66adc52eb4e6339'/>
<id>db16826367fefcb0ddb93d76b66adc52eb4e6339</id>
<content type='text'>
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
  HWPOISON: Enable error_remove_page on btrfs
  HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
  HWPOISON: Add madvise() based injector for hardware poisoned pages v4
  HWPOISON: Enable error_remove_page for NFS
  HWPOISON: Enable .remove_error_page for migration aware file systems
  HWPOISON: The high level memory error handler in the VM v7
  HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
  HWPOISON: shmem: call set_page_dirty() with locked page
  HWPOISON: Define a new error_remove_page address space op for async truncation
  HWPOISON: Add invalidate_inode_page
  HWPOISON: Refactor truncate to allow direct truncating of page v2
  HWPOISON: check and isolate corrupted free pages v2
  HWPOISON: Handle hardware poisoned pages in try_to_unmap
  HWPOISON: Use bitmask/action code for try_to_unmap behaviour
  HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
  HWPOISON: Add poison check to page fault handling
  HWPOISON: Add basic support for poisoned pages in fault handler v3
  HWPOISON: Add new SIGBUS error codes for hardware poison signals
  HWPOISON: Add support for poison swap entries v2
  HWPOISON: Export some rmap vma locking to outside world
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
  HWPOISON: Enable error_remove_page on btrfs
  HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
  HWPOISON: Add madvise() based injector for hardware poisoned pages v4
  HWPOISON: Enable error_remove_page for NFS
  HWPOISON: Enable .remove_error_page for migration aware file systems
  HWPOISON: The high level memory error handler in the VM v7
  HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
  HWPOISON: shmem: call set_page_dirty() with locked page
  HWPOISON: Define a new error_remove_page address space op for async truncation
  HWPOISON: Add invalidate_inode_page
  HWPOISON: Refactor truncate to allow direct truncating of page v2
  HWPOISON: check and isolate corrupted free pages v2
  HWPOISON: Handle hardware poisoned pages in try_to_unmap
  HWPOISON: Use bitmask/action code for try_to_unmap behaviour
  HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
  HWPOISON: Add poison check to page fault handling
  HWPOISON: Add basic support for poisoned pages in fault handler v3
  HWPOISON: Add new SIGBUS error codes for hardware poison signals
  HWPOISON: Add support for poison swap entries v2
  HWPOISON: Export some rmap vma locking to outside world
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>getrusage: fill ru_maxrss value</title>
<updated>2009-09-23T14:39:30+00:00</updated>
<author>
<name>Jiri Pirko</name>
<email>jpirko@redhat.com</email>
</author>
<published>2009-09-22T23:44:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1f10206cf8e945220f7220a809d8bfc15c21f9a5'/>
<id>1f10206cf8e945220f7220a809d8bfc15c21f9a5</id>
<content type='text'>
Make -&gt;ru_maxrss value in struct rusage filled accordingly to rss hiwater
mark.  This struct is filled as a parameter to getrusage syscall.
-&gt;ru_maxrss value is set to KBs which is the way it is done in BSD
systems.  /usr/bin/time (gnu time) application converts -&gt;ru_maxrss to KBs
which seems to be incorrect behavior.  Maintainer of this util was
notified by me with the patch which corrects it and cc'ed.

To make this happen we extend struct signal_struct by two fields.  The
first one is -&gt;maxrss which we use to store rss hiwater of the task.  The
second one is -&gt;cmaxrss which we use to store highest rss hiwater of all
task childs.  These values are used in k_getrusage() to actually fill
-&gt;ru_maxrss.  k_getrusage() uses current rss hiwater value directly if mm
struct exists.

Note:
exec() clear mm-&gt;hiwater_rss, but doesn't clear sig-&gt;maxrss.
it is intetionally behavior. *BSD getrusage have exec() inheriting.

test programs
========================================================

getrusage.c
===========
 #include &lt;stdio.h&gt;
 #include &lt;stdlib.h&gt;
 #include &lt;string.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/time.h&gt;
 #include &lt;sys/resource.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/wait.h&gt;
 #include &lt;unistd.h&gt;
 #include &lt;signal.h&gt;
 #include &lt;sys/mman.h&gt;

 #include "common.h"

 #define err(str) perror(str), exit(1)

int main(int argc, char** argv)
{
	int status;

	printf("allocate 100MB\n");
	consume(100);

	printf("testcase1: fork inherit? \n");
	printf("  expect: initial.self ~= child.self\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
	} else {
		show_rusage("fork child");
		_exit(0);
	}
	printf("\n");

	printf("testcase2: fork inherit? (cont.) \n");
	printf("  expect: initial.children ~= 100MB, but child.children = 0\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
	} else {
		show_rusage("child");
		_exit(0);
	}
	printf("\n");

	printf("testcase3: fork + malloc \n");
	printf("  expect: child.self ~= initial.self + 50MB\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
	} else {
		printf("allocate +50MB\n");
		consume(50);
		show_rusage("fork child");
		_exit(0);
	}
	printf("\n");

	printf("testcase4: grandchild maxrss\n");
	printf("  expect: post_wait.children ~= 300MB\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
		show_rusage("post_wait");
	} else {
		system("./child -n 0 -g 300");
		_exit(0);
	}
	printf("\n");

	printf("testcase5: zombie\n");
	printf("  expect: pre_wait ~= initial, IOW the zombie process is not accounted.\n");
	printf("          post_wait ~= 400MB, IOW wait() collect child's max_rss. \n");
	show_rusage("initial");
	if (__fork()) {
		sleep(1); /* children become zombie */
		show_rusage("pre_wait");
		wait(&amp;status);
		show_rusage("post_wait");
	} else {
		system("./child -n 400");
		_exit(0);
	}
	printf("\n");

	printf("testcase6: SIG_IGN\n");
	printf("  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).\n");
	show_rusage("initial");
	signal(SIGCHLD, SIG_IGN);
	if (__fork()) {
		sleep(1); /* children become zombie */
		show_rusage("after_zombie");
	} else {
		system("./child -n 500");
		_exit(0);
	}
	printf("\n");
	signal(SIGCHLD, SIG_DFL);

	printf("testcase7: exec (without fork) \n");
	printf("  expect: initial ~= exec \n");
	show_rusage("initial");
	execl("./child", "child", "-v", NULL);

	return 0;
}

child.c
=======
 #include &lt;sys/types.h&gt;
 #include &lt;unistd.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/wait.h&gt;
 #include &lt;stdio.h&gt;
 #include &lt;stdlib.h&gt;
 #include &lt;string.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/time.h&gt;
 #include &lt;sys/resource.h&gt;

 #include "common.h"

int main(int argc, char** argv)
{
	int status;
	int c;
	long consume_size = 0;
	long grandchild_consume_size = 0;
	int show = 0;

	while ((c = getopt(argc, argv, "n:g:v")) != -1) {
		switch (c) {
		case 'n':
			consume_size = atol(optarg);
			break;
		case 'v':
			show = 1;
			break;
		case 'g':

			grandchild_consume_size = atol(optarg);
			break;
		default:
			break;
		}
	}

	if (show)
		show_rusage("exec");

	if (consume_size) {
		printf("child alloc %ldMB\n", consume_size);
		consume(consume_size);
	}

	if (grandchild_consume_size) {
		if (fork()) {
			wait(&amp;status);
		} else {
			printf("grandchild alloc %ldMB\n", grandchild_consume_size);
			consume(grandchild_consume_size);

			exit(0);
		}
	}

	return 0;
}

common.c
========
 #include &lt;stdio.h&gt;
 #include &lt;stdlib.h&gt;
 #include &lt;string.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/time.h&gt;
 #include &lt;sys/resource.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/wait.h&gt;
 #include &lt;unistd.h&gt;
 #include &lt;signal.h&gt;
 #include &lt;sys/mman.h&gt;

 #include "common.h"
 #define err(str) perror(str), exit(1)

void show_rusage(char *prefix)
{
    	int err, err2;
    	struct rusage rusage_self;
    	struct rusage rusage_children;

    	printf("%s: ", prefix);
    	err = getrusage(RUSAGE_SELF, &amp;rusage_self);
    	if (!err)
    		printf("self %ld ", rusage_self.ru_maxrss);
    	err2 = getrusage(RUSAGE_CHILDREN, &amp;rusage_children);
    	if (!err2)
    		printf("children %ld ", rusage_children.ru_maxrss);

    	printf("\n");
}

/* Some buggy OS need this worthless CPU waste. */
void make_pagefault(void)
{
	void *addr;
	int size = getpagesize();
	int i;

	for (i=0; i&lt;1000; i++) {
		addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
		if (addr == MAP_FAILED)
			err("make_pagefault");
		memset(addr, 0, size);
		munmap(addr, size);
	}
}

void consume(int mega)
{
    	size_t sz = mega * 1024 * 1024;
    	void *ptr;

    	ptr = malloc(sz);
    	memset(ptr, 0, sz);
	make_pagefault();
}

pid_t __fork(void)
{
	pid_t pid;

	pid = fork();
	make_pagefault();

	return pid;
}

common.h
========
void show_rusage(char *prefix);
void make_pagefault(void);
void consume(int mega);
pid_t __fork(void);

FreeBSD result (expected result)
========================================================
allocate 100MB
testcase1: fork inherit?
  expect: initial.self ~= child.self
initial: self 103492 children 0
fork child: self 103540 children 0

testcase2: fork inherit? (cont.)
  expect: initial.children ~= 100MB, but child.children = 0
initial: self 103540 children 103540
child: self 103564 children 0

testcase3: fork + malloc
  expect: child.self ~= initial.self + 50MB
initial: self 103564 children 103564
allocate +50MB
fork child: self 154860 children 0

testcase4: grandchild maxrss
  expect: post_wait.children ~= 300MB
initial: self 103564 children 154860
grandchild alloc 300MB
post_wait: self 103564 children 308720

testcase5: zombie
  expect: pre_wait ~= initial, IOW the zombie process is not accounted.
          post_wait ~= 400MB, IOW wait() collect child's max_rss.
initial: self 103564 children 308720
child alloc 400MB
pre_wait: self 103564 children 308720
post_wait: self 103564 children 411312

testcase6: SIG_IGN
  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).
initial: self 103564 children 411312
child alloc 500MB
after_zombie: self 103624 children 411312

testcase7: exec (without fork)
  expect: initial ~= exec
initial: self 103624 children 411312
exec: self 103624 children 411312

Linux result (actual test result)
========================================================
allocate 100MB
testcase1: fork inherit?
  expect: initial.self ~= child.self
initial: self 102848 children 0
fork child: self 102572 children 0

testcase2: fork inherit? (cont.)
  expect: initial.children ~= 100MB, but child.children = 0
initial: self 102876 children 102644
child: self 102572 children 0

testcase3: fork + malloc
  expect: child.self ~= initial.self + 50MB
initial: self 102876 children 102644
allocate +50MB
fork child: self 153804 children 0

testcase4: grandchild maxrss
  expect: post_wait.children ~= 300MB
initial: self 102876 children 153864
grandchild alloc 300MB
post_wait: self 102876 children 307536

testcase5: zombie
  expect: pre_wait ~= initial, IOW the zombie process is not accounted.
          post_wait ~= 400MB, IOW wait() collect child's max_rss.
initial: self 102876 children 307536
child alloc 400MB
pre_wait: self 102876 children 307536
post_wait: self 102876 children 410076

testcase6: SIG_IGN
  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).
initial: self 102876 children 410076
child alloc 500MB
after_zombie: self 102880 children 410076

testcase7: exec (without fork)
  expect: initial ~= exec
initial: self 102880 children 410076
exec: self 102880 children 410076

Signed-off-by: Jiri Pirko &lt;jpirko@redhat.com&gt;
Signed-off-by: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Hugh Dickins &lt;hugh.dickins@tiscali.co.uk&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make -&gt;ru_maxrss value in struct rusage filled accordingly to rss hiwater
mark.  This struct is filled as a parameter to getrusage syscall.
-&gt;ru_maxrss value is set to KBs which is the way it is done in BSD
systems.  /usr/bin/time (gnu time) application converts -&gt;ru_maxrss to KBs
which seems to be incorrect behavior.  Maintainer of this util was
notified by me with the patch which corrects it and cc'ed.

To make this happen we extend struct signal_struct by two fields.  The
first one is -&gt;maxrss which we use to store rss hiwater of the task.  The
second one is -&gt;cmaxrss which we use to store highest rss hiwater of all
task childs.  These values are used in k_getrusage() to actually fill
-&gt;ru_maxrss.  k_getrusage() uses current rss hiwater value directly if mm
struct exists.

Note:
exec() clear mm-&gt;hiwater_rss, but doesn't clear sig-&gt;maxrss.
it is intetionally behavior. *BSD getrusage have exec() inheriting.

test programs
========================================================

getrusage.c
===========
 #include &lt;stdio.h&gt;
 #include &lt;stdlib.h&gt;
 #include &lt;string.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/time.h&gt;
 #include &lt;sys/resource.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/wait.h&gt;
 #include &lt;unistd.h&gt;
 #include &lt;signal.h&gt;
 #include &lt;sys/mman.h&gt;

 #include "common.h"

 #define err(str) perror(str), exit(1)

int main(int argc, char** argv)
{
	int status;

	printf("allocate 100MB\n");
	consume(100);

	printf("testcase1: fork inherit? \n");
	printf("  expect: initial.self ~= child.self\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
	} else {
		show_rusage("fork child");
		_exit(0);
	}
	printf("\n");

	printf("testcase2: fork inherit? (cont.) \n");
	printf("  expect: initial.children ~= 100MB, but child.children = 0\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
	} else {
		show_rusage("child");
		_exit(0);
	}
	printf("\n");

	printf("testcase3: fork + malloc \n");
	printf("  expect: child.self ~= initial.self + 50MB\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
	} else {
		printf("allocate +50MB\n");
		consume(50);
		show_rusage("fork child");
		_exit(0);
	}
	printf("\n");

	printf("testcase4: grandchild maxrss\n");
	printf("  expect: post_wait.children ~= 300MB\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&amp;status);
		show_rusage("post_wait");
	} else {
		system("./child -n 0 -g 300");
		_exit(0);
	}
	printf("\n");

	printf("testcase5: zombie\n");
	printf("  expect: pre_wait ~= initial, IOW the zombie process is not accounted.\n");
	printf("          post_wait ~= 400MB, IOW wait() collect child's max_rss. \n");
	show_rusage("initial");
	if (__fork()) {
		sleep(1); /* children become zombie */
		show_rusage("pre_wait");
		wait(&amp;status);
		show_rusage("post_wait");
	} else {
		system("./child -n 400");
		_exit(0);
	}
	printf("\n");

	printf("testcase6: SIG_IGN\n");
	printf("  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).\n");
	show_rusage("initial");
	signal(SIGCHLD, SIG_IGN);
	if (__fork()) {
		sleep(1); /* children become zombie */
		show_rusage("after_zombie");
	} else {
		system("./child -n 500");
		_exit(0);
	}
	printf("\n");
	signal(SIGCHLD, SIG_DFL);

	printf("testcase7: exec (without fork) \n");
	printf("  expect: initial ~= exec \n");
	show_rusage("initial");
	execl("./child", "child", "-v", NULL);

	return 0;
}

child.c
=======
 #include &lt;sys/types.h&gt;
 #include &lt;unistd.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/wait.h&gt;
 #include &lt;stdio.h&gt;
 #include &lt;stdlib.h&gt;
 #include &lt;string.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/time.h&gt;
 #include &lt;sys/resource.h&gt;

 #include "common.h"

int main(int argc, char** argv)
{
	int status;
	int c;
	long consume_size = 0;
	long grandchild_consume_size = 0;
	int show = 0;

	while ((c = getopt(argc, argv, "n:g:v")) != -1) {
		switch (c) {
		case 'n':
			consume_size = atol(optarg);
			break;
		case 'v':
			show = 1;
			break;
		case 'g':

			grandchild_consume_size = atol(optarg);
			break;
		default:
			break;
		}
	}

	if (show)
		show_rusage("exec");

	if (consume_size) {
		printf("child alloc %ldMB\n", consume_size);
		consume(consume_size);
	}

	if (grandchild_consume_size) {
		if (fork()) {
			wait(&amp;status);
		} else {
			printf("grandchild alloc %ldMB\n", grandchild_consume_size);
			consume(grandchild_consume_size);

			exit(0);
		}
	}

	return 0;
}

common.c
========
 #include &lt;stdio.h&gt;
 #include &lt;stdlib.h&gt;
 #include &lt;string.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/time.h&gt;
 #include &lt;sys/resource.h&gt;
 #include &lt;sys/types.h&gt;
 #include &lt;sys/wait.h&gt;
 #include &lt;unistd.h&gt;
 #include &lt;signal.h&gt;
 #include &lt;sys/mman.h&gt;

 #include "common.h"
 #define err(str) perror(str), exit(1)

void show_rusage(char *prefix)
{
    	int err, err2;
    	struct rusage rusage_self;
    	struct rusage rusage_children;

    	printf("%s: ", prefix);
    	err = getrusage(RUSAGE_SELF, &amp;rusage_self);
    	if (!err)
    		printf("self %ld ", rusage_self.ru_maxrss);
    	err2 = getrusage(RUSAGE_CHILDREN, &amp;rusage_children);
    	if (!err2)
    		printf("children %ld ", rusage_children.ru_maxrss);

    	printf("\n");
}

/* Some buggy OS need this worthless CPU waste. */
void make_pagefault(void)
{
	void *addr;
	int size = getpagesize();
	int i;

	for (i=0; i&lt;1000; i++) {
		addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
		if (addr == MAP_FAILED)
			err("make_pagefault");
		memset(addr, 0, size);
		munmap(addr, size);
	}
}

void consume(int mega)
{
    	size_t sz = mega * 1024 * 1024;
    	void *ptr;

    	ptr = malloc(sz);
    	memset(ptr, 0, sz);
	make_pagefault();
}

pid_t __fork(void)
{
	pid_t pid;

	pid = fork();
	make_pagefault();

	return pid;
}

common.h
========
void show_rusage(char *prefix);
void make_pagefault(void);
void consume(int mega);
pid_t __fork(void);

FreeBSD result (expected result)
========================================================
allocate 100MB
testcase1: fork inherit?
  expect: initial.self ~= child.self
initial: self 103492 children 0
fork child: self 103540 children 0

testcase2: fork inherit? (cont.)
  expect: initial.children ~= 100MB, but child.children = 0
initial: self 103540 children 103540
child: self 103564 children 0

testcase3: fork + malloc
  expect: child.self ~= initial.self + 50MB
initial: self 103564 children 103564
allocate +50MB
fork child: self 154860 children 0

testcase4: grandchild maxrss
  expect: post_wait.children ~= 300MB
initial: self 103564 children 154860
grandchild alloc 300MB
post_wait: self 103564 children 308720

testcase5: zombie
  expect: pre_wait ~= initial, IOW the zombie process is not accounted.
          post_wait ~= 400MB, IOW wait() collect child's max_rss.
initial: self 103564 children 308720
child alloc 400MB
pre_wait: self 103564 children 308720
post_wait: self 103564 children 411312

testcase6: SIG_IGN
  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).
initial: self 103564 children 411312
child alloc 500MB
after_zombie: self 103624 children 411312

testcase7: exec (without fork)
  expect: initial ~= exec
initial: self 103624 children 411312
exec: self 103624 children 411312

Linux result (actual test result)
========================================================
allocate 100MB
testcase1: fork inherit?
  expect: initial.self ~= child.self
initial: self 102848 children 0
fork child: self 102572 children 0

testcase2: fork inherit? (cont.)
  expect: initial.children ~= 100MB, but child.children = 0
initial: self 102876 children 102644
child: self 102572 children 0

testcase3: fork + malloc
  expect: child.self ~= initial.self + 50MB
initial: self 102876 children 102644
allocate +50MB
fork child: self 153804 children 0

testcase4: grandchild maxrss
  expect: post_wait.children ~= 300MB
initial: self 102876 children 153864
grandchild alloc 300MB
post_wait: self 102876 children 307536

testcase5: zombie
  expect: pre_wait ~= initial, IOW the zombie process is not accounted.
          post_wait ~= 400MB, IOW wait() collect child's max_rss.
initial: self 102876 children 307536
child alloc 400MB
pre_wait: self 102876 children 307536
post_wait: self 102876 children 410076

testcase6: SIG_IGN
  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).
initial: self 102876 children 410076
child alloc 500MB
after_zombie: self 102880 children 410076

testcase7: exec (without fork)
  expect: initial ~= exec
initial: self 102880 children 410076
exec: self 102880 children 410076

Signed-off-by: Jiri Pirko &lt;jpirko@redhat.com&gt;
Signed-off-by: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Hugh Dickins &lt;hugh.dickins@tiscali.co.uk&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Do the big rename: Performance Counters -&gt; Performance Events</title>
<updated>2009-09-21T12:28:04+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2009-09-21T10:02:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cdd6c482c9ff9c55475ee7392ec8f672eddb7be6'/>
<id>cdd6c482c9ff9c55475ee7392ec8f672eddb7be6</id>
<content type='text'>
Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\&lt;event\&gt;/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )

Suggested-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Paul Mackerras &lt;paulus@samba.org&gt;
Reviewed-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: &lt;linux-arch@vger.kernel.org&gt;
LKML-Reference: &lt;new-submission&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\&lt;event\&gt;/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )

Suggested-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Paul Mackerras &lt;paulus@samba.org&gt;
Reviewed-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: &lt;linux-arch@vger.kernel.org&gt;
LKML-Reference: &lt;new-submission&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process</title>
<updated>2009-09-16T09:50:14+00:00</updated>
<author>
<name>Andi Kleen</name>
<email>andi@firstfloor.org</email>
</author>
<published>2009-09-16T09:50:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4db96cf077aa938b11fe7ac79ecc9b29ec00fbab'/>
<id>4db96cf077aa938b11fe7ac79ecc9b29ec00fbab</id>
<content type='text'>
This allows processes to override their early/late kill
behaviour on hardware memory errors.

Typically applications which are memory error aware is
better of with early kill (see the error as soon
as possible), all others with late kill (only
see the error when the error is really impacting execution)

There's a global sysctl, but this way an application
can set its specific policy.

We're using two bits, one to signify that the process
stated its intention and that

I also made the prctl future proof by enforcing
the unused arguments are 0.

The state is inherited to children.

Note this makes us officially run out of process flags
on 32bit, but the next patch can easily add another field.

Manpage patch will be supplied separately.

Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This allows processes to override their early/late kill
behaviour on hardware memory errors.

Typically applications which are memory error aware is
better of with early kill (see the error as soon
as possible), all others with late kill (only
see the error when the error is really impacting execution)

There's a global sysctl, but this way an application
can set its specific policy.

We're using two bits, one to signify that the process
stated its intention and that

I also made the prctl future proof by enforcing
the unused arguments are 0.

The state is inherited to children.

Note this makes us officially run out of process flags
on 32bit, but the next patch can easily add another field.

Manpage patch will be supplied separately.

Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
