linux/arch/x86
Michel Lespinasse a31a369b07 x86 rwsem: avoid taking slow path when stealing write lock
modify __down_write[_nested] and __down_write_trylock to grab the write
lock whenever the active count is 0, even if there are queued waiters
(they must be writers pending wakeup, since the active count is 0).

Note that this is an optimization only; architectures without this
optimization will still work fine:

- __down_write() would take the slow path which would take the wait_lock
  and then try stealing the lock (as in the spinlocked rwsem implementation)

- __down_write_trylock() would fail, but callers must be ready to deal
  with that - since there are some writers pending wakeup, they could
  have raced with us and obtained the lock before we steal it.

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-07 07:20:17 -07:00
..
boot * The EFI variable anti-bricking algorithm merged in -rc8 broke booting 2013-04-25 14:00:22 -07:00
configs x86: Default to ARCH=x86 to avoid overriding CONFIG_64BIT 2012-12-20 14:37:18 -08:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2013-02-25 15:56:15 -08:00
ia32 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
include x86 rwsem: avoid taking slow path when stealing write lock 2013-05-07 07:20:17 -07:00
kernel Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-21 10:25:42 -07:00
kvm KVM: Allow cross page reads and writes from cached translations. 2013-04-07 13:05:35 +03:00
lguest x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal 2013-04-10 11:25:10 -07:00
lib x86-64: Fix the failure case in copy_user_handle_tail() 2013-03-18 11:32:03 -07:00
math-emu
mm Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-14 11:13:24 -07:00
net x86: bpf_jit_comp: add pkt_type support 2013-01-30 22:38:34 -05:00
oprofile oprofile, x86: Fix wrapping bug in op_x86_get_ctrl() 2012-10-15 14:38:24 +02:00
pci Bug-fixes: 2013-03-03 14:22:53 -08:00
platform x86,efi: Implement efi_no_storage_paranoia parameter 2013-04-17 15:13:38 +01:00
power perf,x86: fix kernel crash with PEBS/BTS after suspend/resume 2013-03-15 09:26:35 -07:00
realmode Merge remote-tracking branch 'origin/x86/mm' into x86/mm2 2013-02-01 02:28:36 -08:00
syscalls fix compat truncate/ftruncate 2013-02-25 09:24:55 -05:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-05 07:57:09 +11:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
vdso timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet() 2013-02-15 12:13:18 +01:00
video
xen Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-14 11:13:24 -07:00
.gitignore
Kbuild
Kconfig Merge remote-tracking branch 'efi/urgent' into x86/urgent 2013-04-19 17:09:03 -07:00
Kconfig.cpu x86, 386 removal: Document Nx586 as a 386 and thus unsupported 2012-11-29 13:28:39 -08:00
Kconfig.debug
Makefile Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:12:03 -08:00
Makefile.um
Makefile_32.cpu x86, 386 removal: Remove CONFIG_M386 from Kconfig 2012-11-29 13:23:01 -08:00