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  1. 22 Dec, 2011 1 commit
    • Kay Sievers's avatar
      arm: convert sysdev_class to a regular subsystem · 4a858cfc
      Kay Sievers authored 
      After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Boojin Kim <boojin.kim@samsung.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: default avatarKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      4a858cfc
  3. 21 Dec, 2011 13 commits
  5. 15 Dec, 2011 1 commit
  7. 14 Dec, 2011 7 commits
  9. 13 Dec, 2011 3 commits
    • Peter Zijlstra's avatar
      kref: Remove the memory barriers · 3c8ed889
      Peter Zijlstra authored 
      Commit 1b0b3b99 ("kref: fix CPU ordering with respect to krefs")
wrongly adds memory barriers to kref.

It states:

  some atomic operations are only atomic, not ordered. Thus a CPU is allowed
  to reorder memory references to an object to before the reference is
  obtained. This fixes it.

While true, it fails to show why this is a problem. I say it is not a
problem because if there is a race with kref_put() such that we could
end up referencing a free'd object without this memory barrier, we
would still have that race with the memory barrier.

The kref_put() in question could complete (and free the object) before
the atomic_inc() and we'd still be up shit creek.

The kref_init() case is even worse, if your object is published at this
time you're so wrong the memory barrier won't make a difference what
so ever. If its not published, the act of publishing should include
the needed barriers/locks to make sure all writes prior to the act of
publishing are complete such that others will only observe a complete
object.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      3c8ed889
    • Peter Zijlstra's avatar
      kref: Implement kref_put in terms of kref_sub · 47dbd7d9
      Peter Zijlstra authored 
      Less lines of code is better.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      47dbd7d9
    • Peter Zijlstra's avatar
      kref: Inline all functions · 4af679cd
      Peter Zijlstra authored 
      These are tiny functions, there's no point in having them out-of-line.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-8eccvi2ur2fzgi00xdjlbf5z@git.kernel.orgSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      4af679cd
  11. 12 Dec, 2011 5 commits
  13. 10 Dec, 2011 5 commits
  15. 27 Nov, 2011 5 commits
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