linux/arch
David S. Miller 270c10e00a sparc64: Fix cpu strand yielding.
For atomic backoff, we just loop over an exponentially backed off
counter.  This is extremely ineffective as it doesn't actually yield
the cpu strand so that other competing strands can use the cpu core.

In cpus previous to SPARC-T4 we have to do this in a slightly hackish
way, by doing an operation with no side effects that also happens to
mark the strand as unavailable.

The mechanism we choose for this is three reads of the %ccr
(condition-code) register into %g0 (the zero register).

SPARC-T4 has an explicit "pause" instruction, and we'll make use of
that in a subsequent commit.

Yield strands also in cpu_relax().  We really should have done this a
very long time ago.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-27 18:35:27 -07:00
..
alpha alpha: separate thread-synchronous flags 2012-10-24 05:16:45 +03:00
arm Serial fix for 3.7-rc3 2012-10-26 10:26:08 -07:00
arm64 arm64: fix alignment padding in assembly code 2012-10-20 11:12:01 +01:00
avr32 Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
blackfin Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
c6x Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
cris Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
frv FRV: Fix const sections change 2012-10-16 18:49:15 -07:00
h8300 Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
hexagon Hexagon: Copyright marking changes 2012-10-18 17:07:21 -05:00
ia64 UAPI: Make arch/ia64/include/asm/kvm_para.h generic 2012-10-18 17:27:43 -07:00
m32r Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
m68k m68k: Wire up kcmp 2012-10-19 17:49:37 +02:00
microblaze Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-10-18 11:49:39 -07:00
mn10300 UAPI: Make arch/mn10300/include/uapi/asm/setup.h non-empty 2012-10-17 12:32:35 +01:00
openrisc Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
parisc UAPI: (Scripted) Disintegrate arch/parisc/include/asm 2012-10-16 21:28:05 +01:00
powerpc cpuidle/powerpc: Fix snooze state problem in the cpuidle design on pseries. 2012-10-18 10:57:25 +11:00
s390 s390,uapi: do not use uapi/asm-generic/kvm_para.h 2012-10-19 11:07:18 +02:00
score Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
sh UAPI: Make arch/sh/include/uapi/asm/hw_breakpoint.h non-empty 2012-10-17 12:32:35 +01:00
sparc sparc64: Fix cpu strand yielding. 2012-10-27 18:35:27 -07:00
tile arch/tile: avoid build warnings from duplicate ELF_R_xxx #defines 2012-10-23 10:22:48 -04:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-13 10:05:52 +09:00
unicore32 Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-26 09:35:46 -07:00
xtensa xtensa: add missing system calls to the syscall table 2012-10-19 10:46:44 -07:00
.gitignore
Kconfig Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00