Hi Alex I found a patch, It could let NO_HZ_FULL running on 32bits. Do you means when I merged this patch. It could work well on kernel v3.10?
-----邮件原件----- 发件人: Alex Shi [mailto:alex.shi@linaro.org] 发送时间: 2013年11月19日 11:15 收件人: Sunshaojie; Shaojie Sun; viresh kumar 抄送: Vincent Guittot; Fathi Boudra; Guodong Xu; Amit Kucheria; Chris Redpath; Linaro Kernel; LAK; Frédéric Weisbecker; Kevin Hilman 主题: Re: 答复: a bug on NO_HZ_FULL_ALL
On 11/19/2013 11:10 AM, Sunshaojie wrote:
Hi Alex
I tested it on kernel V3.10 and on 32bits ARM system. Where did you see this option opened only for 64bits?
kernel/time/Kconfig:
config NO_HZ_FULL bool "Full dynticks system (tickless)" # NO_HZ_COMMON dependency depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS # We need at least one periodic CPU for timekeeping depends on SMP # RCU_USER_QS dependency depends on HAVE_CONTEXT_TRACKING # VIRT_CPU_ACCOUNTING_GEN dependency depends on 64BIT <======= select NO_HZ_COMMON select RCU_USER_QS select RCU_NOCB_CPU select VIRT_CPU_ACCOUNTING_GEN select IRQ_WORK
-----邮件原件----- 发件人: Alex Shi [mailto:alex.shi@linaro.org] 发送时间: 2013年11月19日 11:03 收件人: Shaojie Sun; viresh kumar 抄送: Vincent Guittot; Fathi Boudra; Guodong Xu; Amit Kucheria; Chris Redpath; Linaro Kernel; LAK; Frédéric Weisbecker; Kevin Hilman; Sunshaojie 主题: Re: a bug on NO_HZ_FULL_ALL
On 11/14/2013 05:54 PM, Shaojie Sun wrote:
No, I think it is a bug.
Because I tested the option with NO_HZ_FULL and without NO_HZ_FULL_ALL. It had only little interruptes on CPU0 twd. With same code, I added NO_HZ_FULL_ALL option. It had too many interruptes on CPU0 twd.
So the sumbitter just didn't test twd interrupts, when he expanded NO_HZ_FULL option to all cpu.
On Thu, Nov 14, 2013 at 4:09 PM, viresh kumar viresh.kumar@linaro.org wrote:
On Thursday 14 November 2013 01:35 PM, Vincent Guittot wrote:
AFAICT, It's a none issue. In full nohz, a timer fires periodically (around 4sec period on ARM IIRC) on one cpu (cpu0).
Timer should always be running on CPU0, its out of nohz-full domain. Its cpu 1, where it will fire after long delays..
https://wiki.linaro.org/WorkingGroups/PowerManagement/Doc/AdaptiveTi c kless
Shaojie, which kernel version has this bug? I just find only the v3.13 kernel has opened the NO_HZ_FULL for 32 bit kernel. and my testing base it.
but for lsk, it is 3.10 kernel, so unless you are using 64bit kernel to do testing, is it right?
-- Thanks Alex
-- Thanks Alex