linux-toradex.git/kernel/cpu.c, branch tegra-10.7.1

sched: Fix set_cpu_active() in cpu_down()

2010-04-09T03:07:14+00:00

Sachin found cpu hotplug test failures on powerpc, which made
the kernel hang on his POWER box.

The problem is that we fail to re-activate a cpu when a
hot-unplug fails. Fix this by moving the de-activation into
_cpu_down after doing the initial checks.

Remove the synchronize_sched() calls and rely on those implied
by rebuilding the sched domains using the new mask.

Reported-by: Sachin Sant 
Signed-off-by: Xiaotian Feng 
Tested-by: Sachin Sant 
Signed-off-by: Peter Zijlstra 
Cc: Mike Galbraith 
LKML-Reference: <20091216170517.500272612@chello.nl>
Signed-off-by: Ingo Molnar

timers, init: Limit the number of per cpu calibration bootup messages

2010-01-28T23:01:14+00:00

commit feae3203d711db0a9965300ee6d592257fdaae4f upstream.

Limit the number of per cpu calibration messages by only
printing out results for the first cpu to boot.

Also, don't print "CPUx is down" as this is expected, and we
don't need 4096 reminders... ;-)

Signed-off-by: Mike Travis 
Cc: Heiko Carstens 
Cc: Roland Dreier 
Cc: Randy Dunlap 
Cc: Tejun Heo 
Cc: Andi Kleen 
Cc: Greg Kroah-Hartman 
Cc: Yinghai Lu 
Cc: David Rientjes 
Cc: Steven Rostedt 
Cc: Rusty Russell 
Cc: Hidetoshi Seto 
Cc: Jack Steiner 
Cc: Frederic Weisbecker 
LKML-Reference: <20091118002219.889552000@alcatraz.americas.sgi.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched: Fix balance vs hotplug race

2010-01-06T23:04:49+00:00

commit 6ad4c18884e864cf4c77f9074d3d1816063f99cd upstream.

Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo
sched domain managment) we have cpu_active_mask which is suppose to rule
scheduler migration and load-balancing, except it never (fully) did.

The particular problem being solved here is a crash in try_to_wake_up()
where select_task_rq() ends up selecting an offline cpu because
select_task_rq_fair() trusts the sched_domain tree to reflect the
current state of affairs, similarly select_task_rq_rt() trusts the
root_domain.

However, the sched_domains are updated from CPU_DEAD, which is after the
cpu is taken offline and after stop_machine is done. Therefore it can
race perfectly well with code assuming the domains are right.

Cure this by building the domains from cpu_active_mask on
CPU_DOWN_PREPARE.

Signed-off-by: Peter Zijlstra 
LKML-Reference: 
Signed-off-by: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Holger Hoffstätte 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-09-15T16:19:38+00:00

* 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, pat: Fix cacheflush address in change_page_attr_set_clr()
  mm: remove !NUMA condition from PAGEFLAGS_EXTENDED condition set
  x86: Fix earlyprintk=dbgp for machines without NX
  x86, pat: Sanity check remap_pfn_range for RAM region
  x86, pat: Lookup the protection from memtype list on vm_insert_pfn()
  x86, pat: Add lookup_memtype to get the current memtype of a paddr
  x86, pat: Use page flags to track memtypes of RAM pages
  x86, pat: Generalize the use of page flag PG_uncached
  x86, pat: Add rbtree to do quick lookup in memtype tracking
  x86, pat: Add PAT reserve free to io_mapping* APIs
  x86, pat: New i/f for driver to request memtype for IO regions
  x86, pat: ioremap to follow same PAT restrictions as other PAT users
  x86, pat: Keep identity maps consistent with mmaps even when pat_disabled
  x86, mtrr: make mtrr_aps_delayed_init static bool
  x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init
  generic-ipi: Allow cpus not yet online to call smp_call_function with irqs disabled
  x86: Fix an incorrect argument of reserve_bootmem()
  x86: Fix system crash when loading with "reservetop" parameter

x86, intel_txt: clean up the impact on generic code, unbreak non-x86

2009-09-02T01:25:07+00:00

Move tboot.h from asm to linux to fix the build errors of intel_txt
patch on non-X86 platforms. Remove the tboot code from generic code
init/main.c and kernel/cpu.c.

Signed-off-by: Shane Wang 
Signed-off-by: H. Peter Anvin

x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init

2009-08-21T23:25:55+00:00

SDM Vol 3a section titled "MTRR considerations in MP systems" specifies
the need for synchronizing the logical cpu's while initializing/updating
MTRR.

Currently Linux kernel does the synchronization of all cpu's only when
a single MTRR register is programmed/updated. During an AP online
(during boot/cpu-online/resume)  where we initialize all the MTRR/PAT registers,
we don't follow this synchronization algorithm.

This can lead to scenarios where during a dynamic cpu online, that logical cpu
is initializing MTRR/PAT with cache disabled (cr0.cd=1) etc while other logical
HT sibling continue to run (also with cache disabled because of cr0.cd=1
on its sibling).

Starting from Westmere, VMX transitions with cr0.cd=1 don't work properly
(because of some VMX performance optimizations) and the above scenario
(with one logical cpu doing VMX activity and another logical cpu coming online)
can result in system crash.

Fix the MTRR initialization by doing rendezvous of all the cpus. During
boot and resume, we delay the MTRR/PAT init for APs till all the
logical cpu's come online and the rendezvous process at the end of AP's bringup,
will initialize the MTRR/PAT for all AP's.

For dynamic single cpu online, we synchronize all the logical cpus and
do the MTRR/PAT init on the AP that is coming online.

Signed-off-by: Suresh Siddha 
Signed-off-by: H. Peter Anvin

x86, intel_txt: Intel TXT Sx shutdown support

2009-07-21T18:50:04+00:00

Support for graceful handling of sleep states (S3/S4/S5) after an Intel(R) TXT launch.

Without this patch, attempting to place the system in one of the ACPI sleep
states (S3/S4/S5) will cause the TXT hardware to treat this as an attack and
will cause a system reset, with memory locked.  Not only may the subsequent
memory scrub take some time, but the platform will be unable to enter the
requested power state.

This patch calls back into the tboot so that it may properly and securely clean
up system state and clear the secrets-in-memory flag, after which it will place
the system into the requested sleep state using ACPI information passed by the kernel.

 arch/x86/kernel/smpboot.c     |    2 ++
 drivers/acpi/acpica/hwsleep.c |    3 +++
 kernel/cpu.c                  |    7 ++++++-
 3 files changed, 11 insertions(+), 1 deletion(-)

Signed-off-by: Joseph Cihula 
Signed-off-by: Shane Wang 
Signed-off-by: H. Peter Anvin

mm/init: cpu_hotplug_init() must be initialized before SLAB

2009-06-23T04:18:12+00:00

SLAB uses get/put_online_cpus() which use a mutex which is itself only
initialized when cpu_hotplug_init() is called.  Currently we hang suring
boot in SLAB due to doing that too late.

Reported by James Bottomley and Sachin Sant (and possibly others).
Debugged by Benjamin Herrenschmidt.

This just removes the dynamic initialization of the data structures, and
replaces it with a static one, avoiding this dependency entirely, and
removing one unnecessary special initcall.

Tested-by: Sachin Sant 
Tested-by: James Bottomley 
Tested-by: Benjamin Herrenschmidt 
Signed-off-by: Linus Torvalds

cpumask: use set_cpu_active in init/main.c

2009-03-30T11:35:12+00:00

cpu_active_map is deprecated in favor of cpu_active_mask, which is
const for safety: we use accessors now (set_cpu_active) is we really
want to make a change.

Signed-off-by: Rusty Russell

stop_machine/cpu hotplug: fix disable_nonboot_cpus

2009-01-07T19:36:14+00:00

disable_nonboot_cpus calls _cpu_down. But _cpu_down requires that the
caller already created the stop_machine workqueue (like cpu_down does).
Otherwise a call to stop_machine will lead to accesses to random memory
regions.

When introducing this new interface (9ea09af3bd3090e8349ca2899ca2011bd94cda85
"stop_machine: introduce stop_machine_create/destroy") I missed the second
call site of _cpu_down.
So add the missing stop_machine_create/destroy calls to disable_nonboot_cpus
as well.

Fixes suspend-to-ram/disk and also this bug:

[  286.547348] BUG: unable to handle kernel paging request at 6b6b6b6b
[  286.548940] IP: [] __stop_machine+0x88/0xe3
[  286.550598] Oops: 0002 [#1] SMP
[  286.560580] Pid: 3273, comm: halt Not tainted (2.6.28-06127-g238c6d5
[  286.560580] EIP: is at __stop_machine+0x88/0xe3
[  286.560580] Process halt (pid: 3273, ti=f1a28000 task=f4530f30
[  286.560580] Call Trace:
[  286.560580]  [] ? _cpu_down+0x10f/0x234
[  286.560580]  [] ? disable_nonboot_cpus+0x58/0xdc
[  286.560580]  [] ? kernel_poweroff+0x22/0x39
[  286.560580]  [] ? sys_reboot+0xde/0x14c
[  286.560580]  [] ? complete_signal+0x179/0x191
[  286.560580]  [] ? send_signal+0x1cc/0x1e1
[  286.560580]  [] ? _spin_unlock_irqrestore+0x2d/0x3c
[  286.560580]  [] ? group_send_signal_info+0x58/0x61
[  286.560580]  [] ? kill_pid_info+0x30/0x3a
[  286.560580]  [] ? sys_kill+0x75/0x13a
[  286.560580]  [] ? mntput_no_expire+ox1f/0x101
[  286.560580]  [] ? dput+0x1e/0x105
[  286.560580]  [] ?  __fput+0x150/0x158
[  286.560580]  [] ? audit_syscall_entry+0x137/0x159
[  286.560580]  [] ? sysenter_do_call+0x12/0x34

Reported-and-tested-by: "Justin P. Mattock" 
Reviewed-by: Pekka Enberg 
Signed-off-by: Heiko Carstens 
Tested-by: Ingo Molnar 
Signed-off-by: Linus Torvalds