android_kernel_xiaomi_sm7250/include/asm-ia64
Christoph Lameter f521089158 [IA64] Spinlock optimizations
1. Nontemporal store for spin unlock.

A nontemporal store will not update the LRU setting for the cacheline. The
cacheline with the lock may therefore be evicted faster from the cpu
caches. Doing so may be useful since it increases the chance that the
exclusive cache line has been evicted when another cpu is trying to
acquire the lock.

The time between dropping and reacquiring a lock on the same cpu is
typically very small so the danger of the cacheline being
evicted is negligible.

2. Avoid semaphore operation in write_unlock and use nontemporal store

write_lock uses a cmpxchg like the regular spin_lock but write_unlock uses
clear_bit which requires a load and then a loop over a cmpxchg. The
following patch makes write_unlock simply use a nontemporal store to clear
the highest 8 bits. We will then still have the lower 3 bytes (24 bits)
left to count the readers.

Doing the byte store will reduce the number of possible readers from 2^31
to 2^24 = 16 million.

These patches were discussed already:

http://marc.theaimsgroup.com/?t=111472054400001&r=1&w=2
http://marc.theaimsgroup.com/?l=linux-ia64&m=111401837707849&w=2

The nontemporal stores will only work using GCC. If a compiler is used
that does not support inline asm then fallback C code is used. This
will preserve the byte store but not be able to do the nontemporal stores.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-08-10 16:13:10 -07:00
..
sn [IA64] Altix pcibus_to_node implementation 2005-07-12 16:12:55 -07:00
a.out.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
acpi-ext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
acpi.h [ACPI] Evaluate CPEI Processor Override flag 2005-07-12 00:01:41 -04:00
agp.h [PATCH] AGP fix for Xen VMM 2005-06-07 12:35:43 -07:00
asmmacro.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
atomic.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
bitops.h [IA64] fix fls() 2005-04-21 11:07:59 -07:00
break.h [PATCH] Kprobes/IA64: kdebug die notification mechanism 2005-06-23 09:45:22 -07:00
bug.h [PATCH] remove all kernel BUGs 2005-05-01 08:59:01 -07:00
bugs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
byteorder.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cache.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cacheflush.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
checksum.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
compat.h [PATCH] compat: introduce compat_time_t 2005-06-23 09:45:32 -07:00
cpu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cputime.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
current.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cyclone.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
delay.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
div64.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dma-mapping.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dma.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
elf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
emergency-restart.h [PATCH] Add emergency_restart() 2005-07-26 14:35:41 -07:00
errno.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fcntl.h [PATCH] Don't force O_LARGEFILE for 32 bit processes on ia64 2005-06-23 09:45:28 -07:00
fpswa.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fpu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
gcc_intrin.h [IA64] fix fls() 2005-04-21 11:07:59 -07:00
hardirq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
hdreg.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
hw_irq.h [IA64] assign_irq_vector() should not panic 2005-07-11 10:30:07 -07:00
ia32.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ia64regs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ide.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
intel_intrin.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
intrinsics.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
io.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctl.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctls.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
iosapic.h [PATCH] ACPI based I/O APIC hot-plug: ia64 support 2005-06-27 21:52:44 -07:00
ipcbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
irq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kdebug.h [PATCH] Kprobes/IA64: kdebug die notification mechanism 2005-06-23 09:45:22 -07:00
kmap_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kprobes.h [PATCH] Return probe redesign: ia64 specific implementation 2005-06-27 15:23:53 -07:00
kregs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
linkage.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
local.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_dig.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_hpsim.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_hpzx1_swiotlb.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_hpzx1.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_init.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_sn2.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mc146818rtc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca_asm.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
meminit.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mman.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmu_context.h [IA64] Fix another IA64 preemption problem 2005-06-28 10:01:19 -07:00
mmu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmzone.h [IA64] Fix pfn_to_nid() so the kernel compiles again for !CONFIG_DISCONTIGMEM. 2005-06-23 14:52:51 -07:00
module.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msgbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msi.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
namei.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
nodedata.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
numa.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
numnodes.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
page.h [PATCH] freepgt: hugetlb_free_pgd_range 2005-04-19 13:29:16 -07:00
pal.h [IA64] multi-core/multi-thread identification 2005-04-25 13:25:06 -07:00
param.h [PATCH] ia64: Selectable Timer Interrupt Frequency 2005-06-23 09:45:10 -07:00
parport.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
patch.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pci.h Auto merge with /home/aegl/GIT/linus 2005-07-13 12:15:43 -07:00
percpu.h [PATCH] adjust per_cpu definition in non-SMP case 2005-06-23 09:45:28 -07:00
perfmon_default_smpl.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfmon.h [IA64] alternate perfmon handler 2005-05-18 16:14:30 -07:00
pgalloc.h [IA64] re-enable preempt before page allocation for pgtable quicklist 2005-04-26 09:04:31 -07:00
pgtable.h [PATCH] Hugepage consolidation 2005-06-21 18:46:15 -07:00
poll.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
posix_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
processor.h [PATCH] ia64: fix floating-point preemption problem 2005-06-08 16:21:14 -07:00
ptrace_offsets.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ptrace.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
resource.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rse.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rwsem.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sal.h [IA64] multi-core/multi-thread identification 2005-04-25 13:25:06 -07:00
scatterlist.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sections.h [PATCH] kprobes/ia64: refuse kprobe on ivt code 2005-06-27 15:23:54 -07:00
segment.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
semaphore.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sembuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
serial.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
setup.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
shmbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
shmparam.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sigcontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
siginfo.h [PATCH] consolidate SIGEV_PAD_SIZE 2005-05-01 08:59:08 -07:00
signal.h [PATCH] asm/signal.h unification 2005-05-04 07:33:15 -07:00
smp.h [PATCH] smp_processor_id() cleanup 2005-06-21 18:46:13 -07:00
socket.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sockios.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
spinlock.h [IA64] Spinlock optimizations 2005-08-10 16:13:10 -07:00
stat.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
statfs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
string.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
suspend.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
system.h [PATCH] sched: cleanup context switch locking 2005-06-25 16:24:43 -07:00
termbits.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
termios.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
thread_info.h [PATCH] streamline preempt_count type across archs 2005-06-23 09:45:19 -07:00
timex.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tlb.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tlbflush.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
topology.h [IA64] pcibus_to_node implementation for IA64 2005-07-12 11:04:22 -07:00
types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uaccess.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ucontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
unaligned.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uncached.h [PATCH] ia64 uncached alloc 2005-06-21 18:46:18 -07:00
unistd.h [IA64] inotify: ia64 syscalls. 2005-07-27 10:46:12 -07:00
unwind.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
user.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ustack.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vga.h [IA64-SGI] pcdp: add PCDP pci interface support 2005-06-28 09:09:06 -07:00
xor.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00