korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-05 01:54:09 +08:00
Code Issues Packages Projects Releases Wiki Activity
f312deb4cd
linux/arch/powerpc/kernel
History
Anton Blanchard 8d165db107 powerpc: Improve decrementer accuracy 
I have been looking at sources of OS jitter and notice that after a long
NO_HZ idle period we wakeup too early:

relative time (us)    event
                      timer irq exit
    999946.405        timer irq entry
         4.835        timer irq exit
        21.685        timer irq entry
         3.540          timer (tick_sched_timer) entry

Here we slept for just under a second then took a timer interrupt that did
nothing. 21.685 us later we wake up again and do the work.

We set a rather low shift value of 16 for the decrementer clockevent, which I
think is causing this issue. On this box we have a 207MHz decrementer and see:

clockevent: decrementer mult[3501] shift[16] cpu[0]

For calculations of large intervals this mult/shift combination could be
off by a significant amount. I notice the sparc code has a loop that iterates
to find a mult/shift combination that maximises the shift value while
keeping mult under 32bit. With the patch below we get:

clockevent: decrementer mult[35015c20] shift[32] cpu[15]

And we no longer see the spurious wakeups.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-21 15:44:24 +10:00
..
vdso32 powerpc/mm: Introduce MMU features 2008-12-21 14:21:16 +11:00
vdso64 powerpc/mm: Introduce MMU features 2008-12-21 14:21:16 +11:00
.gitignore powerpc: Ignore generated vmlinux.lds in git 2008-10-07 14:26:18 +11:00
align.c powerpc: Fix load/store float double alignment handler 2009-02-26 14:02:53 +11:00
asm-offsets.c Merge commit 'origin/master' into next 2009-03-30 14:04:53 +11:00
audit.c [PATCH] audit signal recipients 2007-05-11 05:38:25 -04:00
btext.c powerpc: Use the common ascii hex helpers 2008-08-20 16:34:57 +10:00
cacheinfo.c powerpc/cacheinfo: Rename cache_dir per-cpu variable 2009-01-13 14:48:02 +11:00
cacheinfo.h powerpc: Rewrite sysfs processor cache info code 2009-01-08 16:25:10 +11:00
clock.c [POWERPC] clk.h interface for platforms 2007-10-03 09:11:56 +10:00
compat_audit.c [PATCH] add SIGNAL syscall class (v3) 2007-05-11 05:38:25 -04:00
cpu_setup_6xx.S powerpc/mm: e300c2/c3/c4 TLB errata workaround 2009-03-24 13:47:32 +11:00
cpu_setup_44x.S AMCC PPC 460SX redwood SoC platform initial framework 2009-02-14 14:41:29 -05:00
cpu_setup_fsl_booke.S powerpc/fsl-booke: Cleanup init/exception setup to be runtime 2009-01-28 18:16:50 -06:00
cpu_setup_pa6t.S
cpu_setup_ppc970.S powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit 2008-09-15 11:08:35 -07:00
cputable.c powerpc: Add 2.06 tlbie mnemonics 2009-05-21 15:44:21 +10:00
crash_dump.c powerpc: Unify opcode definitions and support 2009-02-23 10:48:56 +11:00
crash.c powerpc: Increase CRASH_HANDLER_MAX 2008-06-30 22:31:00 +10:00
dbell.c powerpc: Add support for using doorbells for SMP IPI 2009-02-23 15:53:03 +11:00
dma-iommu.c powerpc: Change u64/s64 to a long long integer type 2009-01-13 14:47:59 +11:00
dma.c dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32) 2009-04-07 08:31:11 -07:00
entry_32.S powerpc: Unify opcode definitions and support 2009-02-23 10:48:56 +11:00
entry_64.S powerpc64, ftrace: save toc only on modules for function graph 2009-02-23 10:48:54 +11:00
firmware.c
fpu.S powerpc: Disable VSX or current process in giveup_fpu/altivec 2009-04-07 15:18:59 +10:00
ftrace.c powerpc/ftrace: Fix printf format warning 2009-04-07 15:19:00 +10:00
head_8xx.S powerpc: convert to use __HEAD and HEAD_TEXT macros. 2009-04-26 09:20:38 -07:00
head_32.S powerpc: convert to use __HEAD and HEAD_TEXT macros. 2009-04-26 09:20:38 -07:00
head_40x.S powerpc: convert to use __HEAD and HEAD_TEXT macros. 2009-04-26 09:20:38 -07:00
head_44x.S powerpc: convert to use __HEAD and HEAD_TEXT macros. 2009-04-26 09:20:38 -07:00
head_64.S powerpc/kconfig: Kill PPC_MULTIPLATFORM 2009-03-11 17:11:35 +11:00
head_booke.h Merge commit 'jwb/next' into next 2009-03-03 13:30:03 +11:00
head_fsl_booke.S powerpc: convert to use __HEAD and HEAD_TEXT macros. 2009-04-26 09:20:38 -07:00
ibmebus.c powerpc: struct device - replace bus_id with dev_name(), dev_set_name() 2008-12-16 15:53:38 +11:00
idle_6xx.S powerpc: Fix for getting CPU number in power_save_ppc32_restore() 2008-09-03 20:53:47 +10:00
idle_e500.S powerpc: Fix for getting CPU number in power_save_ppc32_restore() 2008-09-03 20:53:47 +10:00
idle_power4.S
idle.c powerpc: ftrace, do not latency trace idle 2008-11-20 10:51:15 -08:00
init_task.c take init_fs to saner place 2008-12-31 18:07:42 -05:00
io.c ftrace: support for PowerPC 2008-05-23 22:43:11 +02:00
iomap.c [POWERPC] Add 64-bit resources support to pci_iomap 2007-09-20 07:36:52 -05:00
iommu.c powerpc: Change u64/s64 to a long long integer type 2009-01-13 14:47:59 +11:00
irq.c powerpc/irq: Remove fallback to __do_IRQ() 2009-05-21 15:44:20 +10:00
isa-bridge.c [POWERPC] Remove leftover printk in isa-bridge.c 2008-05-09 20:22:59 +10:00
kgdb.c kgdb, x86, arm, mips, powerpc: ignore user space single stepping 2008-09-26 10:36:41 -05:00
kprobes.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-01-07 11:31:52 -08:00
l2cr_6xx.S Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
legacy_serial.c powerpc/powermac: Fixup default serial port device for pmac_zilog 2008-07-28 16:30:53 +10:00
lparcfg.c powerpc/pseries: Add dispatch dispersion statistics 2009-04-07 15:18:59 +10:00
machine_kexec_32.c kexec jump: rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE 2008-08-15 08:35:42 -07:00
machine_kexec_64.c powerpc/32: Setup OF properties for kdump 2008-12-23 15:13:29 +11:00
machine_kexec.c powerpc: Allow mem=x cmdline to work with 4G+ 2009-05-15 16:43:41 +10:00
Makefile powerpc/kconfig: Kill PPC_MULTIPLATFORM 2009-03-11 17:11:35 +11:00
misc_32.S powerpc/44x: Support 16K/64K base page sizes on 44x 2008-12-29 09:53:25 +11:00
misc_64.S powerpc: Disable VSX or current process in giveup_fpu/altivec 2009-04-07 15:18:59 +10:00
misc.S powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit 2008-09-15 11:08:35 -07:00
module_32.c powerpc/ppc32: ftrace, dynamic ftrace to handle modules 2008-11-20 10:52:53 -08:00
module_64.c powerpc: Unify opcode definitions and support 2009-02-23 10:48:56 +11:00
module.c powerpc/mm: Introduce MMU features 2008-12-21 14:21:16 +11:00
msi.c powerpc/PCI: include pci.h in powerpc MSI implementation 2009-03-25 08:54:29 -07:00
nvram_64.c [POWERPC] pseries: Eliminate global error_log_cnt variable 2007-08-17 11:01:52 +10:00
of_device.c powerpc: struct device - replace bus_id with dev_name(), dev_set_name() 2008-12-16 15:53:38 +11:00
of_platform.c dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32) 2009-04-07 08:31:11 -07:00
paca.c powerpc: Update page-in counter for CMM 2008-11-05 22:08:28 +11:00
pci_32.c powerpc/pci: Remove redundant pcnet32 fixup 2009-05-21 15:44:24 +10:00
pci_64.c powerpc/pci: Remove redundant pcnet32 fixup 2009-05-21 15:44:24 +10:00
pci_dn.c powerpc/pci: Move pseries code into pseries platform specific area 2009-05-21 15:44:24 +10:00
pci-common.c powerpc: Fix PCI ROM access 2009-05-15 16:43:42 +10:00
pmc.c [POWERPC] Made FSL Book-E PMC support more generic 2008-02-05 23:34:14 -06:00
ppc32.h powerpc: Add VSX context save/restore, ptrace and signal support 2008-07-01 11:28:50 +10:00
ppc_ksyms.c powerpc: Export cacheable_memzero as its now used in a driver 2009-01-08 16:25:17 +11:00
ppc_save_regs.S powerpc: Prepare xmon_save_regs for use with kdump 2008-12-23 15:13:28 +11:00
proc_ppc64.c powerpc: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
process.c Simplify copy_thread() 2009-04-02 19:04:51 -07:00
prom_init_check.sh powerpc: Print linux_banner in prom_init 2009-03-11 17:11:33 +11:00
prom_init.c powerpc/pseries: Fix ibm,client-architecture comment 2009-04-07 15:18:59 +10:00
prom_parse.c powerpc: Fix of_node_put() exit path in of_irq_map_one() 2009-04-20 12:18:43 -06:00
prom.c powerpc: Allow mem=x cmdline to work with 4G+ 2009-05-15 16:43:41 +10:00
ptrace32.c powerpc: Fix ptrace compat wrapper for FPU register access 2009-04-07 15:19:00 +10:00
ptrace.c powerpc: Don't use the wrong thread_struct for ptrace get/set VSX regs 2008-07-30 15:26:54 +10:00
reloc_64.S powerpc: Make the 64-bit kernel as a position-independent executable 2008-09-15 11:08:38 -07:00
rtas_flash.c proc 2/2: remove struct proc_dir_entry::owner 2009-03-31 01:14:44 +04:00
rtas_pci.c powerpc/pci: Clean up direct access to sysdata by RTAS 2009-05-21 15:44:23 +10:00
rtas-proc.c [POWERPC] Fix sparse warnings in arch/powerpc/kernel 2008-05-14 22:31:59 +10:00
rtas-rtc.c
rtas.c powerpc/pseries: Fix partition migration hang under load 2009-02-23 15:53:04 +11:00
setup_32.c powerpc/32: Wire up the trampoline code for kdump 2008-12-23 15:13:29 +11:00
setup_64.c powerpc/mm: Introduce early_init_mmu() on 64-bit 2009-03-24 13:47:34 +11:00
setup-common.c powerpc: Remove duplicated #include's 2009-04-07 15:18:58 +10:00
setup.h
signal_32.c powerpc: Sanitize stack pointer in signal handling code 2009-03-27 16:58:24 +11:00
signal_64.c powerpc: Sanitize stack pointer in signal handling code 2009-03-27 16:58:24 +11:00
signal.c powerpc: Sanitize stack pointer in signal handling code 2009-03-27 16:58:24 +11:00
signal.h powerpc: Sanitize stack pointer in signal handling code 2009-03-27 16:58:24 +11:00
smp-tbsync.c powerpc: Silence software timebase sync 2008-11-05 22:08:28 +11:00
smp.c Merge branch 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-02 11:44:09 -08:00
softemu8xx.c Remove asm/a.out.h files for all architectures without a.out support. 2008-09-06 19:30:24 +01:00
stacktrace.c powerpc: Removed duplicated include in stacktrace.c 2008-07-28 16:30:47 +10:00
suspend.c PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
swsusp_32.S powerpc/mm: Introduce MMU features 2008-12-21 14:21:16 +11:00
swsusp_64.c
swsusp_asm64.S powerpc: Fix 64-bit hibernation with 64k pages 2008-10-07 14:26:20 +11:00
swsusp.c powerpc/mm: Split mmu_context handling 2008-12-21 14:21:15 +11:00
sys_ppc32.c compat: generic compat get/settimeofday 2008-10-16 11:21:33 -07:00
syscalls.c powerpc/mm: Add Strong Access Ordering support 2008-07-09 16:30:45 +10:00
sysfs.c powerpc: Fix bugs introduced by sysfs changes 2009-03-27 16:58:24 +11:00
systbl_chk.c [POWERPC] Fix a couple of copyright symbols 2008-01-25 22:52:50 +11:00
systbl_chk.sh [POWERPC] Fix a couple of copyright symbols 2008-01-25 22:52:50 +11:00
systbl.S [POWERPC] Align the sys_call_table 2007-10-11 14:36:47 +10:00
tau_6xx.c on_each_cpu(): kill unused 'retry' parameter 2008-06-26 11:24:38 +02:00
time.c powerpc: Improve decrementer accuracy 2009-05-21 15:44:24 +10:00
traps.c powerpc: Add support for using doorbells for SMP IPI 2009-02-23 15:53:03 +11:00
udbg_16550.c powerpc/udbg: Fix lost byte during console handover; change LFCR to CRLF 2009-03-11 17:11:34 +11:00
udbg.c powerpc/udbg: Fix lost byte during console handover; change LFCR to CRLF 2009-03-11 17:11:34 +11:00
vdso.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2008-12-28 16:54:33 -08:00
vecemu.c
vector.S
vio.c workqueue: add to_delayed_work() helper function 2009-04-02 19:04:50 -07:00
vmlinux.lds.S powerpc: Revert switch to TEXT_TEXT in linker script 2009-04-28 15:55:14 -07:00