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  1. 25 Aug, 2011 7 commits
    • Tejun Heo's avatar
      mtrr: fix UP breakage caused during switch to stop_machine · cbbfa38f
      Tejun Heo authored 
      While removing custom rendezvous code and switching to stop_machine,
commit 192d8857 ("x86, mtrr: use stop_machine APIs for doing MTRR
rendezvous") completely dropped mtrr setting code on !CONFIG_SMP
breaking MTRR settting on UP.

Fix it by removing the incorrect CONFIG_SMP.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarAnders Eriksson <aeriksson@fastmail.fm>
Tested-and-acked-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cbbfa38f
    • Josh Boyer's avatar
      lockdep: Add helper function for dir vs file i_mutex annotation · e096d0c7
      Josh Boyer authored 
      Purely in-memory filesystems do not use the inode hash as the dcache
tells us if an entry already exists.  As a result, they do not call
unlock_new_inode, and thus directory inodes do not get put into a
different lockdep class for i_sem.

We need the different lockdep classes, because the locking order for
i_mutex is different for directory inodes and regular inodes.  Directory
inodes can do "readdir()", which takes i_mutex *before* possibly taking
mm->mmap_sem (due to a page fault while copying the directory entry to
user space).

In contrast, regular inodes can be mmap'ed, which takes mm->mmap_sem
before accessing i_mutex.

The two cases can never happen for the same inode, so no real deadlock
can occur, but without the different lockdep classes, lockdep cannot
understand that.  As a result, if CONFIG_DEBUG_LOCK_ALLOC is set, this
can lead to false positives from lockdep like below:

    find/645 is trying to acquire lock:
     (&mm->mmap_sem){++++++}, at: [<ffffffff81109514>] might_fault+0x5c/0xac

    but task is already holding lock:
     (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff81149f34>]
    vfs_readdir+0x5b/0xb4

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 (&sb->s_type->i_mutex_key#15){+.+.+.}:
          [<ffffffff8108ac26>] lock_acquire+0xbf/0x103
          [<ffffffff814db822>] __mutex_lock_common+0x4c/0x361
          [<ffffffff814dbc46>] mutex_lock_nested+0x40/0x45
          [<ffffffff811daa87>] hugetlbfs_file_mmap+0x82/0x110
          [<ffffffff81111557>] mmap_region+0x258/0x432
          [<ffffffff811119dd>] do_mmap_pgoff+0x2ac/0x306
          [<ffffffff81111b4f>] sys_mmap_pgoff+0x118/0x16a
          [<ffffffff8100c858>] sys_mmap+0x22/0x24
          [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b

    -> #0 (&mm->mmap_sem){++++++}:
          [<ffffffff8108a4bc>] __lock_acquire+0xa1a/0xcf7
          [<ffffffff8108ac26>] lock_acquire+0xbf/0x103
          [<ffffffff81109541>] might_fault+0x89/0xac
          [<ffffffff81149cff>] filldir+0x6f/0xc7
          [<ffffffff811586ea>] dcache_readdir+0x67/0x205
          [<ffffffff81149f54>] vfs_readdir+0x7b/0xb4
          [<ffffffff8114a073>] sys_getdents+0x7e/0xd1
          [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b

This patch moves the directory vs file lockdep annotation into a helper
function that can be called by in-memory filesystems and has hugetlbfs
call it.
Signed-off-by: default avatarJosh Boyer <jwboyer@redhat.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e096d0c7
    • Linus Torvalds's avatar
      Merge branch 'urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback · e33f2d23
      Linus Torvalds authored 
      * 'urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback:
  squeeze max-pause area and drop pass-good area
      e33f2d23
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/cpupowerutils · be5378f3
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/brodo/cpupowerutils:
  cpupower: use man(1) when calling "cpupower help subcommand"
  cpupower: make NLS truly optional
  cpupower: fix Makefile typo
  cpupower: Make monitor command -c/--cpu aware
  cpupower: Better detect offlined CPUs
  cpupower: Do not show an empty Idle_Stats monitor if no idle driver is available
  cpupower: mperf monitor - Use TSC to calculate max frequency if possible
  cpupower: avoid using symlinks
      be5378f3
    • Linus Torvalds's avatar
      Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging · e5b1d9cc
      Linus Torvalds authored 
      * 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
  hwmon: (i5k_amb) Drop i5k_channel_pci_id
  hwmon: (ntc_thermistor) Simplify if sequence
      e5b1d9cc
    • Linus Torvalds's avatar
      Merge branch '3.1-rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending · f385b697
      Linus Torvalds authored 
      * '3.1-rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (21 commits)
  target: Convert acl_node_lock to be IRQ-disabling
  target: Make locking in transport_deregister_session() IRQ safe
  tcm_fc: init/exit functions should not be protected by "#ifdef MODULE"
  target: Print subpage too for unhandled MODE SENSE pages
  iscsi-target: Fix iscsit_allocate_se_cmd_for_tmr failure path bugs
  iscsi-target: Implement iSCSI target IPv6 address printing.
  target: Fix task SGL chaining breakage with transport_allocate_data_tasks
  target: Fix task count > 1 handling breakage and use max_sector page alignment
  target: Add missing DATA_SG_IO transport_cmd_get_valid_sectors check
  target: Fix SYNCHRONIZE_CACHE zero LBA + range breakage
  target: Remove duplicate task completions in transport_emulate_control_cdb
  target: Fix WRITE_SAME usage with transport_get_size
  target: Add WRITE_SAME (10) parsing and refactor passthrough checks
  target: Fix write payload exception handling with ->new_cmd_map
  iscsi-target: forever loop bug in iscsit_attach_ooo_cmdsn()
  iscsi-target: remove duplicate return
  target: Convert target_core_rd.c to use use BUG_ON
  iscsi-target: Fix leak on failure in iscsi_copy_param_list()
  target: Use ERR_CAST inlined function
  target: Make standard INQUIRY return 'not connected' for tpg_virt_lun0
  ...
      f385b697
    • Andi Kleen's avatar
      Add a personality to report 2.6.x version numbers · be27425d
      Andi Kleen authored 
      I ran into a couple of programs which broke with the new Linux 3.0
version.  Some of those were binary only.  I tried to use LD_PRELOAD to
work around it, but it was quite difficult and in one case impossible
because of a mix of 32bit and 64bit executables.

For example, all kind of management software from HP doesnt work, unless
we pretend to run a 2.6 kernel.

  $ uname -a
  Linux svivoipvnx001 3.0.0-08107-g97cd98f #1062 SMP Fri Aug 12 18:11:45 CEST 2011 i686 i686 i386 GNU/Linux

  $ hpacucli ctrl all show

  Error: No controllers detected.

  $ rpm -qf /usr/sbin/hpacucli
  hpacucli-8.75-12.0

Another notable case is that Python now reports "linux3" from
sys.platform(); which in turn can break things that were checking
sys.platform() == "linux2":

  https://bugzilla.mozilla.org/show_bug.cgi?id=664564

It seems pretty clear to me though it's a bug in the apps that are using
'==' instead of .startswith(), but this allows us to unbreak broken
programs.

This patch adds a UNAME26 personality that makes the kernel report a
2.6.40+x version number instead.  The x is the x in 3.x.

I know this is somewhat ugly, but I didn't find a better workaround, and
compatibility to existing programs is important.

Some programs also read /proc/sys/kernel/osrelease.  This can be worked
around in user space with mount --bind (and a mount namespace)

To use:

  wget ftp://ftp.kernel.org/pub/linux/kernel/people/ak/uname26/uname26.c
  gcc -o uname26 uname26.c
  ./uname26 program
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      be27425d
  3. 24 Aug, 2011 12 commits
  5. 23 Aug, 2011 18 commits
  7. 22 Aug, 2011 3 commits
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