linux_old1/arch/sh/include/asm
Christian Borntraeger 79ab11cdb9 locking/core: Introduce cpu_relax_yield()
For spinning loops people do often use barrier() or cpu_relax().
For most architectures cpu_relax and barrier are the same, but on
some architectures cpu_relax can add some latency.
For example on power,sparc64 and arc, cpu_relax can shift the CPU
towards other hardware threads in an SMT environment.
On s390 cpu_relax does even more, it uses an hypercall to the
hypervisor to give up the timeslice.
In contrast to the SMT yielding this can result in larger latencies.
In some places this latency is unwanted, so another variant
"cpu_relax_lowlatency" was introduced. Before this is used in more
and more places, lets revert the logic and provide a cpu_relax_yield
that can be called in places where yielding is more important than
latency. By default this is the same as cpu_relax on all architectures.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1477386195-32736-2-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-16 10:15:09 +01:00
..
Kbuild locking/rwsem, sh: Drop superfluous arch specific implementation 2016-04-13 10:42:19 +02:00
adc.h
addrspace.h sh: nommu: use 32-bit phys mode. 2010-11-04 12:32:24 +09:00
alignment.h
asm-offsets.h
atomic-grb.h locking/atomic, arch/sh: Implement atomic_fetch_{add,sub,and,or,xor}() 2016-06-16 10:48:29 +02:00
atomic-irq.h locking/atomic, arch/sh: Implement atomic_fetch_{add,sub,and,or,xor}() 2016-06-16 10:48:29 +02:00
atomic-llsc.h locking/atomic, arch/sh: Fix ATOMIC_FETCH_OP() 2016-09-22 14:47:02 +02:00
atomic.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
barrier.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
bitops-cas.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
bitops-grb.h
bitops-llsc.h
bitops-op32.h
bitops.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
bl_bit.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
bl_bit_32.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
bl_bit_64.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
bug.h sh: Consolidate die definitions for trap handlers. 2012-06-14 14:18:51 +09:00
bugs.h
cache.h Merge branch 'for-35' of git://repo.or.cz/linux-kbuild 2010-06-01 08:55:52 -07:00
cache_insns.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
cache_insns_32.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
cache_insns_64.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
cacheflush.h sh: Assume new page cache pages have dirty dcache lines. 2010-12-01 15:39:51 +09:00
checksum.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
checksum_32.h ipv6: Pass proto to csum_ipv6_magic as __u8 instead of unsigned short 2016-03-13 23:55:13 -04:00
clock.h sh: sh header sh_clk_ops rename 2012-03-12 22:19:10 +01:00
cmpxchg-cas.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
cmpxchg-grb.h sh: support 1 and 2 byte xchg 2016-01-12 20:47:01 +02:00
cmpxchg-irq.h sh: support 1 and 2 byte xchg 2016-01-12 20:47:01 +02:00
cmpxchg-llsc.h sh: move xchg_cmpxchg to a header by itself 2016-01-12 20:47:02 +02:00
cmpxchg-xchg.h sh: cmpxchg: fix a bit shift bug in big_endian os 2016-07-31 03:33:32 +00:00
cmpxchg.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
device.h sh: Defer to asm-generic/device.h. 2012-01-13 16:27:38 +09:00
dma-mapping.h dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
dma-register.h dmaengine: shdma: Add more register documentation 2014-07-09 10:55:57 +02:00
dma.h sh: Kill off MAX_DMA_ADDRESS leftovers. 2012-05-19 18:50:09 +09:00
dmabrg.h
dwarf.h
elf.h sh: Fix FDPIC binary loader 2013-01-11 21:02:57 +09:00
entry-macros.S
fb.h
fixmap.h sh: use generic fixmap.h 2014-01-23 16:36:54 -08:00
flat.h
fpu.h sh: move fpu_counter into ARCH specific thread_struct 2013-11-13 12:09:13 +09:00
freq.h
ftrace.h ftrace: Format MCOUNT_ADDR address as type unsigned long 2015-07-20 22:30:53 -04:00
futex-cas.h sh: add working futex atomic ops on userspace addresses for smp 2016-08-05 03:29:36 +00:00
futex-irq.h sh: add working futex atomic ops on userspace addresses for smp 2016-08-05 03:29:36 +00:00
futex-llsc.h sh: add working futex atomic ops on userspace addresses for smp 2016-08-05 03:29:36 +00:00
futex.h sh: add working futex atomic ops on userspace addresses for smp 2016-08-05 03:29:36 +00:00
gpio.h sh: Remove unused sh_pfc_register_info() function 2013-01-25 09:24:30 +09:00
hardirq.h
hd64461.h
heartbeat.h
hugetlb.h mm/hugetlb: remove arch_prepare/release_hugepage from arch headers 2015-06-25 17:00:35 -07:00
hw_breakpoint.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
hw_irq.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
i2c-sh7760.h sh: edosk7760 evt2irq migration. 2012-05-18 14:52:31 +09:00
io.h libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
io_generic.h sh: machvec IO death. 2010-11-01 09:49:04 -04:00
io_noioport.h sh: fix build error by adding generic ioport_{map/unmap}() 2014-08-06 18:01:13 -07:00
io_trapped.h Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
irq.h sh: Kill off machvec IRQ hinting. 2012-05-21 17:54:01 +09:00
irqflags.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
kdebug.h sh64: Convert to unwinder API. 2012-05-24 15:03:46 +09:00
kexec.h sh: convert kexec crash kernel management to LMB. 2010-05-07 14:54:55 +09:00
kgdb.h sh: kgdb: Unset CACHE_FLUSH_IS_SAFE for SMP. 2012-04-11 10:48:24 +09:00
kmap_types.h
kprobes.h sh: Add kprobe-based event tracer. 2010-06-14 15:16:53 +09:00
linkage.h
machvec.h Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
mmu.h sh: Fix up NUMA build for 29-bit. 2010-03-10 16:29:48 +09:00
mmu_context.h Fix weird uses of num_online_cpus(). 2015-03-10 13:54:42 +10:30
mmu_context_32.h
mmu_context_64.h
mmzone.h Fix node_start/end_pfn() definition for mm/page_cgroup.c 2011-06-27 14:13:09 -07:00
module.h Make most arch asm/module.h files use asm-generic/module.h 2012-09-28 14:31:03 +09:30
page.h sh: add copy_user_page() alias for __copy_user() 2015-10-16 11:42:28 -07:00
pci.h PCI: Move pci_dma_* helpers to common code 2016-03-07 10:40:02 -06:00
perf_event.h irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
pgalloc.h tree wide: get rid of __GFP_REPEAT for order-0 allocations part I 2016-06-24 17:23:52 -07:00
pgtable-2level.h
pgtable-3level.h
pgtable.h mm: make FIRST_USER_ADDRESS unsigned long on all archs 2015-02-11 17:06:03 -08:00
pgtable_32.h sh: drop _PAGE_FILE and pte_file()-related helpers 2015-02-10 14:30:33 -08:00
pgtable_64.h sh: drop _PAGE_FILE and pte_file()-related helpers 2015-02-10 14:30:33 -08:00
posix_types.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
processor.h locking/core: Introduce cpu_relax_yield() 2016-11-16 10:15:09 +01:00
processor_32.h sh: move fpu_counter into ARCH specific thread_struct 2013-11-13 12:09:13 +09:00
processor_64.h sh: move fpu_counter into ARCH specific thread_struct 2013-11-13 12:09:13 +09:00
ptrace.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
ptrace_32.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
ptrace_64.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
push-switch.h
reboot.h
romimage-macros.h
rtc.h rtc: sh: provide rtc_class_ops directly 2016-06-04 00:22:46 +02:00
seccomp.h
sections.h nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
segment.h sh: macro whitespace fixes 2015-01-13 15:24:08 +02:00
setup.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
sfp-machine.h
sh7760fb.h
sh_bios.h
shmparam.h
siu.h sh: remove unused DMA device pointer from SIU platform data 2012-07-20 11:23:44 +05:30
smc37c93x.h
smp-ops.h sh: CPU hotplug support. 2010-04-26 19:08:55 +09:00
smp.h sh: fix smp-shx3 build regression from removal of arch localtimer 2016-03-29 22:03:50 +00:00
sparsemem.h
spi.h
spinlock-cas.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
spinlock-llsc.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
spinlock.h sh: add J2 atomics using the cas.l instruction 2016-08-05 03:29:34 +00:00
spinlock_types.h
sram.h sh: Provide a generic SRAM pool for tiny memories. 2010-10-15 02:09:00 +09:00
stackprotector.h sh: initial stack protector support. 2012-04-19 15:45:57 +09:00
stacktrace.h sh: remove warning and warning_symbol from struct stacktrace_ops 2011-05-23 14:42:15 +09:00
string.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
string_32.h
string_64.h
suspend.h SH: cpuidle: check error code at init 2013-04-22 00:35:53 +02:00
switch_to.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
switch_to_32.h sched, sh: Fold finish_arch_switch() into switch_to() 2015-08-04 09:38:05 +02:00
switch_to_64.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
syscall.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
syscall_32.h SH: define syscall_get_arch() for superh 2014-09-23 16:20:01 -04:00
syscall_64.h SH: define syscall_get_arch() for superh 2014-09-23 16:20:01 -04:00
syscalls.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
syscalls_32.h sh: push extra copy of r0-r2 for syscall parameters 2014-04-03 16:20:52 -07:00
syscalls_64.h sh: switch to generic fork/vfork/clone 2012-11-28 22:36:47 -05:00
thread_info.h signal: consolidate {TS,TLF}_RESTORE_SIGMASK code 2016-08-02 19:35:23 -04:00
timex.h
tlb.h mm/mmu_gather: track page size with mmu gather and force flush if page size change 2016-07-26 16:19:19 -07:00
tlb_64.h
tlbflush.h sh: Provide a global TLB flush for U/I-TLB clear. 2010-07-02 15:44:09 +09:00
topology.h sh: fix function signature of cpu_coregroup_mask to match pointer type 2016-03-30 00:47:49 +00:00
traps.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
traps_32.h sh: don't pass saved userspace state to exception handlers 2014-04-03 16:20:52 -07:00
traps_64.h sh64: Provide EXPEVT helper. 2012-05-14 13:04:08 +09:00
types.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
uaccess.h exceptions: detritus removal 2016-09-27 21:15:14 -04:00
uaccess_32.h sh: use the new generic strnlen_user() function 2012-06-13 10:28:37 +09:00
uaccess_64.h sh64: failing __get_user() should zero 2016-09-13 17:50:14 -04:00
unaligned-sh4a.h Fix common misspellings 2011-03-31 11:26:23 -03:00
unaligned.h
uncached.h sh: nommu: Support building without an uncached mapping. 2010-11-04 12:46:19 +09:00
unistd.h sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL 2014-06-04 16:54:14 -07:00
unwinder.h
user.h
vga.h
vmlinux.lds.h
watchdog.h
word-at-a-time.h sh: use the new generic strnlen_user() function 2012-06-13 10:28:37 +09:00