linux-toradex.git/kernel, branch v2.6.32-rc3

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2009-10-04T19:39:14+00:00

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (41 commits)
  Revert "Seperate read and write statistics of in_flight requests"
  cfq-iosched: don't delay async queue if it hasn't dispatched at all
  block: Topology ioctls
  cfq-iosched: use assigned slice sync value, not default
  cfq-iosched: rename 'desktop' sysfs entry to 'low_latency'
  cfq-iosched: implement slower async initiate and queue ramp up
  cfq-iosched: delay async IO dispatch, if sync IO was just done
  cfq-iosched: add a knob for desktop interactiveness
  Add a tracepoint for block request remapping
  block: allow large discard requests
  block: use normal I/O path for discard requests
  swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL
  fs/bio.c: move EXPORT* macros to line after function
  Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
  cciss: fix build when !PROC_FS
  block: Do not clamp max_hw_sectors for stacking devices
  block: Set max_sectors correctly for stacking devices
  cciss: cciss_host_attr_groups should be const
  cciss: Dynamically allocate the drive_info_struct for each logical drive.
  cciss: Add usage_count attribute to each logical drive in /sys
  ...

memcg: some modification to softlimit under hierarchical memory reclaim.

2009-10-01T23:11:13+00:00

This patch clean up/fixes for memcg's uncharge soft limit path.

Problems:
  Now, res_counter_charge()/uncharge() handles softlimit information at
  charge/uncharge and softlimit-check is done when event counter per memcg
  goes over limit. Now, event counter per memcg is updated only when
  memory usage is over soft limit. Here, considering hierarchical memcg
  management, ancesotors should be taken care of.

  Now, ancerstors(hierarchy) are handled in charge() but not in uncharge().
  This is not good.

  Prolems:
  1. memcg's event counter incremented only when softlimit hits. That's bad.
     It makes event counter hard to be reused for other purpose.

  2. At uncharge, only the lowest level rescounter is handled. This is bug.
     Because ancesotor's event counter is not incremented, children should
     take care of them.

  3. res_counter_uncharge()'s 3rd argument is NULL in most case.
     ops under res_counter->lock should be small. No "if" sentense is better.

Fixes:
  * Removed soft_limit_xx poitner and checks in charge and uncharge.
    Do-check-only-when-necessary scheme works enough well without them.

  * make event-counter of memcg incremented at every charge/uncharge.
    (per-cpu area will be accessed soon anyway)

  * All ancestors are checked at soft-limit-check. This is necessary because
    ancesotor's event counter may never be modified. Then, they should be
    checked at the same time.

Reviewed-by: Daisuke Nishimura 
Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Paul Menage 
Cc: Li Zefan 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroup: catch bad css refcnt at css_put

2009-10-01T23:11:12+00:00

__css_put() doesn't check a bug as refcnt goes to minus.
I think it should be caught. This patch adds a check for it.

Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Paul Menage 
Cc: Li Zefan 
Cc: Balbir Singh 
Cc: Daisuke Nishimura 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

const: constify remaining file_operations

2009-10-01T23:11:11+00:00

[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan 
Acked-by: Mike Frysinger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

module: fix up CONFIG_KALLSYMS=n build.

2009-10-01T23:11:11+00:00

Starting from commit 4a4962263f07d14660849ec134ee42b63e95ea9a "reduce
symbol table for loaded modules (v2)", the kernel/module.c build is broken
with CONFIG_KALLSYMS disabled.

  CC      kernel/module.o
kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr'
kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token
kernel/module.c: In function 'load_module':
kernel/module.c:2203: error: 'strmap' undeclared (first use in this function)
kernel/module.c:2203: error: (Each undeclared identifier is reported only once
kernel/module.c:2203: error: for each function it appears in.)
kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function)
kernel/module.c:2239: error: implicit declaration of function 'layout_symtab'
kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function)
make[1]: *** [kernel/module.o] Error 1
make: *** [kernel/module.o] Error 2

There are three different issues:

    - layout_symtab() takes a const Elf_Ehdr

    - layout_symtab() needs to return a value

    - symoffs/stroffs/strmap are referenced by the load_module() code
      despite being ifdefed out, which seems unnecessary given the noop
      behaviour of layout_symtab()/add_kallsyms() in the case of
      CONFIG_KALLSYMS=n.

Signed-off-by: Paul Mundt 
Acked-by: Jan Beulich 
Acked-by: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Add a tracepoint for block request remapping

2009-10-01T19:19:34+00:00

Since 2.6.31 now has request-based device-mapper, it's useful to have
a tracepoint for request-remapping as well as bio-remapping.
This patch adds a tracepoint for request-remapping, trace_block_rq_remap().

Signed-off-by: Kiyoshi Ueda 
Signed-off-by: Jun'ichi Nomura 
Cc: Alasdair G Kergon 
Cc: Li Zefan 
Signed-off-by: Jens Axboe

Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs

2009-10-01T19:15:46+00:00

Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
Release kobject also in case the request_fn is NULL.

Problem was noticed via kmemleak backtrace when some sysfs entries were
note properly destroyed during  device removal:

unreferenced object 0xffff88001aa76640 (size 80):
  comm "lvcreate", pid 2120, jiffies 4294885144
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff  .........e......
    90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff  .f........S.....
  backtrace:
    [] kmemleak_alloc+0x26/0x60
    [] kmem_cache_alloc+0x133/0x1c0
    [] sysfs_new_dirent+0x41/0x120
    [] sysfs_add_file_mode+0x3c/0xb0
    [] internal_create_group+0xc1/0x1a0
    [] sysfs_create_group+0x13/0x20
    [] blk_trace_init_sysfs+0x14/0x20
    [] blk_register_queue+0x3c/0xf0
    [] add_disk+0x94/0x160
    [] dm_create+0x598/0x6e0 [dm_mod]
    [] dev_create+0x51/0x350 [dm_mod]
    [] ctl_ioctl+0x1a3/0x240 [dm_mod]
    [] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod]
    [] compat_sys_ioctl+0xcd/0x4f0
    [] sysenter_dispatch+0x7/0x2c
    [] 0xffffffffffffffff

Signed-off-by: Zdenek Kabelac 
Reviewed-by: Li Zefan 
Signed-off-by: Jens Axboe

sched_clock: Fix atomicity/continuity bug by using cmpxchg64()

2009-09-30T20:56:10+00:00

Commit def0a9b2573 (sched_clock: Make it NMI safe) assumed
cmpxchg() of 64bit values was available on X86_32.

That is not so - and causes some subtle scheduler misbehavior due
to incorrect timestamps off to up by ~4 seconds.

Two symptoms are known right now:

 - interactivity problems seen by Arjan: up to 600 msecs
   latencies instead of the expected 20-40 msecs. These
   latencies are very visible on the desktop.

 - incorrect CPU stats: occasionally too high percentages in 'top',
   and crazy CPU usage stats.

Reported-by: Martin Schwidefsky 
Signed-off-by: Eric Dumazet 
Signed-off-by: Arjan van de Ven 
Acked-by: Linus Torvalds 
Cc: John Stultz 
Cc: Peter Zijlstra 
LKML-Reference: <20090930170754.0886ff2e@infradead.org>
Signed-off-by: Ingo Molnar

const: mark struct vm_struct_operations

2009-09-27T18:39:25+00:00

* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

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

2009-09-27T17:39:04+00:00

* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimer: Eliminate needless reprogramming of clock events device