1. 05 Dec, 2011 1 commit
  2. 31 Oct, 2011 1 commit
    • Dan Ballard's avatar
      kernel/sysctl.c: add cap_last_cap to /proc/sys/kernel · 73efc039
      Dan Ballard authored
      Userspace needs to know the highest valid capability of the running
      kernel, which right now cannot reliably be retrieved from the header files
      only.  The fact that this value cannot be determined properly right now
      creates various problems for libraries compiled on newer header files
      which are run on older kernels.  They assume capabilities are available
      which actually aren't.  libcap-ng is one example.  And we ran into the
      same problem with systemd too.
      
      Now the capability is exported in /proc/sys/kernel/cap_last_cap.
      
      [akpm@linux-foundation.org: make cap_last_cap const, per Ulrich]
      Signed-off-by: default avatarDan Ballard <dan@mindstab.net>
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Cc: Ulrich Drepper <drepper@akkadia.org>
      Cc: James Morris <jmorris@namei.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      73efc039
  3. 30 Oct, 2011 1 commit
  4. 14 Aug, 2011 1 commit
  5. 20 Jul, 2011 1 commit
  6. 04 Jun, 2011 1 commit
  7. 23 May, 2011 1 commit
  8. 19 May, 2011 1 commit
    • Chris Metcalf's avatar
      arch/tile: support signal "exception-trace" hook · 571d76ac
      Chris Metcalf authored
      This change adds support for /proc/sys/debug/exception-trace to tile.
      Like x86 and sparc, by default it is set to "1", generating a one-line
      printk whenever a user process crashes.  By setting it to "2", we get
      a much more complete userspace diagnostic at crash time, including
      a user-space backtrace, register dump, and memory dump around the
      address of the crash.
      
      Some vestiges of the Tilera-internal version of this support are
      removed with this patch (the show_crashinfo variable and the
      arch_coredump_signal function).  We retain a "crashinfo" boot parameter
      which allows you to set the boot-time value of exception-trace.
      Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
      571d76ac
  9. 03 Apr, 2011 1 commit
    • Eric Paris's avatar
      capabilites: allow the application of capability limits to usermode helpers · 17f60a7d
      Eric Paris authored
      There is no way to limit the capabilities of usermodehelpers. This problem
      reared its head recently when someone complained that any user with
      cap_net_admin was able to load arbitrary kernel modules, even though the user
      didn't have cap_sys_module.  The reason is because the actual load is done by
      a usermode helper and those always have the full cap set.  This patch addes new
      sysctls which allow us to bound the permissions of usermode helpers.
      
      /proc/sys/kernel/usermodehelper/bset
      /proc/sys/kernel/usermodehelper/inheritable
      
      You must have CAP_SYS_MODULE  and CAP_SETPCAP to change these (changes are
      &= ONLY).  When the kernel launches a usermodehelper it will do so with these
      as the bset and pI.
      
      -v2:	make globals static
      	create spinlock to protect globals
      
      -v3:	require both CAP_SETPCAP and CAP_SYS_MODULE
      -v4:	fix the typo s/CAP_SET_PCAP/CAP_SETPCAP/ because I didn't commit
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      No-objection-from: Serge E. Hallyn <serge.hallyn@canonical.com>
      Acked-by: default avatarDavid Howells <dhowells@redhat.com>
      Acked-by: default avatarSerge E. Hallyn <serge.hallyn@canonical.com>
      Acked-by: default avatarAndrew G. Morgan <morgan@kernel.org>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      17f60a7d
  10. 23 Mar, 2011 2 commits
  11. 08 Mar, 2011 1 commit
    • Al Viro's avatar
      unfuck proc_sysctl ->d_compare() · dfef6dcd
      Al Viro authored
      a) struct inode is not going to be freed under ->d_compare();
      however, the thing PROC_I(inode)->sysctl points to just might.
      Fortunately, it's enough to make freeing that sucker delayed,
      provided that we don't step on its ->unregistering, clear
      the pointer to it in PROC_I(inode) before dropping the reference
      and check if it's NULL in ->d_compare().
      
      b) I'm not sure that we *can* walk into NULL inode here (we recheck
      dentry->seq between verifying that it's still hashed / fetching
      dentry->d_inode and passing it to ->d_compare() and there's no
      negative hashed dentries in /proc/sys/*), but if we can walk into
      that, we really should not have ->d_compare() return 0 on it!
      Said that, I really suspect that this check can be simply killed.
      Nick?
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      dfef6dcd
  12. 23 Feb, 2011 1 commit
  13. 16 Feb, 2011 1 commit
  14. 03 Feb, 2011 1 commit
    • Rik van Riel's avatar
      sched: Use a buddy to implement yield_task_fair() · ac53db59
      Rik van Riel authored
      Use the buddy mechanism to implement yield_task_fair.  This
      allows us to skip onto the next highest priority se at every
      level in the CFS tree, unless doing so would introduce gross
      unfairness in CPU time distribution.
      
      We order the buddy selection in pick_next_entity to check
      yield first, then last, then next.  We need next to be able
      to override yield, because it is possible for the "next" and
      "yield" task to be different processen in the same sub-tree
      of the CFS tree.  When they are, we need to go into that
      sub-tree regardless of the "yield" hint, and pick the correct
      entity once we get to the right level.
      Signed-off-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ac53db59
  15. 01 Feb, 2011 1 commit
  16. 24 Jan, 2011 1 commit
  17. 13 Jan, 2011 3 commits
  18. 09 Dec, 2010 1 commit
  19. 30 Nov, 2010 1 commit
    • Mike Galbraith's avatar
      sched: Add 'autogroup' scheduling feature: automated per session task groups · 5091faa4
      Mike Galbraith authored
      A recurring complaint from CFS users is that parallel kbuild has
      a negative impact on desktop interactivity.  This patch
      implements an idea from Linus, to automatically create task
      groups.  Currently, only per session autogroups are implemented,
      but the patch leaves the way open for enhancement.
      
      Implementation: each task's signal struct contains an inherited
      pointer to a refcounted autogroup struct containing a task group
      pointer, the default for all tasks pointing to the
      init_task_group.  When a task calls setsid(), a new task group
      is created, the process is moved into the new task group, and a
      reference to the preveious task group is dropped.  Child
      processes inherit this task group thereafter, and increase it's
      refcount.  When the last thread of a process exits, the
      process's reference is dropped, such that when the last process
      referencing an autogroup exits, the autogroup is destroyed.
      
      At runqueue selection time, IFF a task has no cgroup assignment,
      its current autogroup is used.
      
      Autogroup bandwidth is controllable via setting it's nice level
      through the proc filesystem:
      
        cat /proc/<pid>/autogroup
      
      Displays the task's group and the group's nice level.
      
        echo <nice level> > /proc/<pid>/autogroup
      
      Sets the task group's shares to the weight of nice <level> task.
      Setting nice level is rate limited for !admin users due to the
      abuse risk of task group locking.
      
      The feature is enabled from boot by default if
      CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via
      the boot option noautogroup, and can also be turned on/off on
      the fly via:
      
        echo [01] > /proc/sys/kernel/sched_autogroup_enabled
      
      ... which will automatically move tasks to/from the root task group.
      Signed-off-by: default avatarMike Galbraith <efault@gmx.de>
      Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
      Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Cc: Paul Turner <pjt@google.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ]
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      5091faa4
  20. 18 Nov, 2010 3 commits
    • Paul Turner's avatar
      sched: Add sysctl_sched_shares_window · a7a4f8a7
      Paul Turner authored
      Introduce a new sysctl for the shares window and disambiguate it from
      sched_time_avg.
      
      A 10ms window appears to be a good compromise between accuracy and performance.
      Signed-off-by: default avatarPaul Turner <pjt@google.com>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <20101115234938.112173964@google.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      a7a4f8a7
    • Peter Zijlstra's avatar
      sched: Rewrite tg_shares_up) · 2069dd75
      Peter Zijlstra authored
      By tracking a per-cpu load-avg for each cfs_rq and folding it into a
      global task_group load on each tick we can rework tg_shares_up to be
      strictly per-cpu.
      
      This should improve cpu-cgroup performance for smp systems
      significantly.
      
      [ Paul: changed to use queueing cfs_rq + bug fixes ]
      Signed-off-by: default avatarPaul Turner <pjt@google.com>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <20101115234937.580480400@google.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      2069dd75
    • Don Zickus's avatar
      x86, nmi_watchdog: Remove the old nmi_watchdog · 5f2b0ba4
      Don Zickus authored
      Now that we have a new nmi_watchdog that is more generic and
      sits on top of the perf subsystem, we really do not need the old
      nmi_watchdog any more.
      
      In addition, the old nmi_watchdog doesn't really work if you are
      using the default clocksource, hpet.  The old nmi_watchdog code
      relied on local apic interrupts to determine if the cpu is still
      alive.  With hpet as the clocksource, these interrupts don't
      increment any more and the old nmi_watchdog triggers false
      postives.
      
      This piece removes the old nmi_watchdog code and stubs out any
      variables and functions calls.  The stubs are the same ones used
      by the new nmi_watchdog code, so it should be well tested.
      Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
      Cc: fweisbec@gmail.com
      Cc: gorcunov@openvz.org
      LKML-Reference: <1289578944-28564-2-git-send-email-dzickus@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      5f2b0ba4
  21. 16 Nov, 2010 1 commit
  22. 12 Nov, 2010 1 commit
  23. 26 Oct, 2010 2 commits
    • Namhyung Kim's avatar
      printk: declare printk_ratelimit_state in ratelimit.h · f5d87d85
      Namhyung Kim authored
      Adding declaration of printk_ratelimit_state in ratelimit.h removes
      potential build breakage and following sparse warning:
      
       kernel/printk.c:1426:1: warning: symbol 'printk_ratelimit_state' was not declared. Should it be static?
      
      [akpm@linux-foundation.org: remove unneeded ifdef]
      Signed-off-by: default avatarNamhyung Kim <namhyung@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f5d87d85
    • Eric Dumazet's avatar
      fs: allow for more than 2^31 files · 518de9b3
      Eric Dumazet authored
      Robin Holt tried to boot a 16TB system and found af_unix was overflowing
      a 32bit value :
      
      <quote>
      
      We were seeing a failure which prevented boot.  The kernel was incapable
      of creating either a named pipe or unix domain socket.  This comes down
      to a common kernel function called unix_create1() which does:
      
              atomic_inc(&unix_nr_socks);
              if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                      goto out;
      
      The function get_max_files() is a simple return of files_stat.max_files.
      files_stat.max_files is a signed integer and is computed in
      fs/file_table.c's files_init().
      
              n = (mempages * (PAGE_SIZE / 1024)) / 10;
              files_stat.max_files = n;
      
      In our case, mempages (total_ram_pages) is approx 3,758,096,384
      (0xe0000000).  That leaves max_files at approximately 1,503,238,553.
      This causes 2 * get_max_files() to integer overflow.
      
      </quote>
      
      Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
      integers, and change af_unix to use an atomic_long_t instead of atomic_t.
      
      get_max_files() is changed to return an unsigned long.  get_nr_files() is
      changed to return a long.
      
      unix_nr_socks is changed from atomic_t to atomic_long_t, while not
      strictly needed to address Robin problem.
      
      Before patch (on a 64bit kernel) :
      # echo 2147483648 >/proc/sys/fs/file-max
      # cat /proc/sys/fs/file-max
      -18446744071562067968
      
      After patch:
      # echo 2147483648 >/proc/sys/fs/file-max
      # cat /proc/sys/fs/file-max
      2147483648
      # cat /proc/sys/fs/file-nr
      704     0       2147483648
      Reported-by: default avatarRobin Holt <holt@sgi.com>
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: default avatarDavid Miller <davem@davemloft.net>
      Reviewed-by: default avatarRobin Holt <holt@sgi.com>
      Tested-by: default avatarRobin Holt <holt@sgi.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Christoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      518de9b3
  24. 25 Oct, 2010 3 commits
    • Christoph Hellwig's avatar
      fs: use percpu counter for nr_dentry and nr_dentry_unused · 312d3ca8
      Christoph Hellwig authored
      The nr_dentry stat is a globally touched cacheline and atomic operation
      twice over the lifetime of a dentry. It is used for the benfit of userspace
      only. Turn it into a per-cpu counter and always decrement it in d_free instead
      of doing various batching operations to reduce lock hold times in the callers.
      
      Based on an earlier patch from Nick Piggin <npiggin@suse.de>.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      312d3ca8
    • Dave Chinner's avatar
      fs: Convert nr_inodes and nr_unused to per-cpu counters · cffbc8aa
      Dave Chinner authored
      The number of inodes allocated does not need to be tied to the
      addition or removal of an inode to/from a list. If we are not tied
      to a list lock, we could update the counters when inodes are
      initialised or destroyed, but to do that we need to convert the
      counters to be per-cpu (i.e. independent of a lock). This means that
      we have the freedom to change the list/locking implementation
      without needing to care about the counters.
      
      Based on a patch originally from Eric Dumazet.
      
      [AV: cleaned up a bit, fixed build breakage on weird configs
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      cffbc8aa
    • Eric Dumazet's avatar
      fs: allow for more than 2^31 files · 7e360c38
      Eric Dumazet authored
      Andrew,
      
      Could you please review this patch, you probably are the right guy to
      take it, because it crosses fs and net trees.
      
      Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
      depend on previous patch (sysctl: fix min/max handling in
      __do_proc_doulongvec_minmax())
      
      Thanks !
      
      [PATCH V4] fs: allow for more than 2^31 files
      
      Robin Holt tried to boot a 16TB system and found af_unix was overflowing
      a 32bit value :
      
      <quote>
      
      We were seeing a failure which prevented boot.  The kernel was incapable
      of creating either a named pipe or unix domain socket.  This comes down
      to a common kernel function called unix_create1() which does:
      
              atomic_inc(&unix_nr_socks);
              if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                      goto out;
      
      The function get_max_files() is a simple return of files_stat.max_files.
      files_stat.max_files is a signed integer and is computed in
      fs/file_table.c's files_init().
      
              n = (mempages * (PAGE_SIZE / 1024)) / 10;
              files_stat.max_files = n;
      
      In our case, mempages (total_ram_pages) is approx 3,758,096,384
      (0xe0000000).  That leaves max_files at approximately 1,503,238,553.
      This causes 2 * get_max_files() to integer overflow.
      
      </quote>
      
      Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
      integers, and change af_unix to use an atomic_long_t instead of
      atomic_t.
      
      get_max_files() is changed to return an unsigned long.
      get_nr_files() is changed to return a long.
      
      unix_nr_socks is changed from atomic_t to atomic_long_t, while not
      strictly needed to address Robin problem.
      
      Before patch (on a 64bit kernel) :
      # echo 2147483648 >/proc/sys/fs/file-max
      # cat /proc/sys/fs/file-max
      -18446744071562067968
      
      After patch:
      # echo 2147483648 >/proc/sys/fs/file-max
      # cat /proc/sys/fs/file-max
      2147483648
      # cat /proc/sys/fs/file-nr
      704     0       2147483648
      Reported-by: default avatarRobin Holt <holt@sgi.com>
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: default avatarDavid Miller <davem@davemloft.net>
      Reviewed-by: default avatarRobin Holt <holt@sgi.com>
      Tested-by: default avatarRobin Holt <holt@sgi.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      7e360c38
  25. 07 Oct, 2010 1 commit
  26. 05 Sep, 2010 1 commit
  27. 09 Aug, 2010 1 commit
  28. 05 Aug, 2010 1 commit
  29. 28 Jul, 2010 2 commits
  30. 23 Jul, 2010 1 commit
  31. 03 Jun, 2010 1 commit