linux/include
Gerald Schaefer 34b133f8e9 [S390] mutex: Introduce arch_mutex_cpu_relax()
The spinning mutex implementation uses cpu_relax() in busy loops as a
compiler barrier. Depending on the architecture, cpu_relax() may do more
than needed in this specific mutex spin loops. On System z we also give
up the time slice of the virtual cpu in cpu_relax(), which prevents
effective spinning on the mutex.

This patch replaces cpu_relax() in the spinning mutex code with
arch_mutex_cpu_relax(), which can be defined by each architecture that
selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so
this patch should not affect other architectures than System z for now.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290437256.7455.4.camel@thinkpad>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-05 12:47:31 +01:00
..
acpi ACPI: video: fix build for CONFIG_ACPI=n 2010-12-11 02:01:46 -05:00
asm-generic asm-generic/stat.h: support 64-bit file time_t for stat() 2010-11-01 15:31:29 -04:00
crypto
drm drm/i915: announce to userspace that the bsd ring is coherent 2010-12-05 10:40:39 +00:00
keys
linux [S390] mutex: Introduce arch_mutex_cpu_relax() 2011-01-05 12:47:31 +01:00
math-emu
media [media] wm8775: Revert changeset fcb9757333 to avoid a regression 2011-01-03 09:09:56 -02:00
mtd mtd: Define MLC Flash as a different flash type 2010-10-25 00:50:20 +01:00
net Revert "ipv4: Allow configuring subnets as local addresses" 2010-12-23 12:03:57 -08:00
pcmcia
rdma IB/core: Add VLAN support for IBoE 2010-10-25 10:20:39 -07:00
rxrpc
scsi SCSI host lock push-down 2010-11-16 13:33:23 -08:00
sound ARM: mach-shmobile: ap4evb: FSI clock use proper process for HDMI 2010-11-24 15:29:56 +09:00
trace ext4: Add new ext4 inode tracepoints 2010-11-08 13:51:33 -05:00
video fbdev: da8xx: punt duplicated FBIO_WAITFORVSYNC define 2010-11-16 10:14:22 +09:00
xen xen: Provide a variant of __RING_SIZE() that is an integer constant expression 2010-12-15 12:34:28 -08:00
Kbuild