Messages in this thread | | | Date | Fri, 16 Jan 2015 16:04:09 +0800 | From | Lai Jiangshan <> | Subject | Re: [RFC PATCH 0/2 shit_A shit_B] workqueue: fix wq_numa bug |
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On 01/16/2015 01:22 PM, Yasuaki Ishimatsu wrote: > Hi Lai, > > Thanks you for posting the patch-set. > > I'll try your it next Monday. So, please wait a while. >
I think it is just waste for testing before the maintainer make the decision. (discussions/ideas are welcome.)
Before TJ's decision, maybe you can do this at first:
"Make numa code maintain the mapping to the best of its knowledge and invoke notification callbacks when it changes. "
Thanks, Lai
> Thanks, > Yasuaki Ishimatsu > > > (2015/01/14 17:54), Lai Jiangshan wrote: >> Hi, All >> >> This patches are un-changloged, un-compiled, un-booted, un-tested, >> they are just shits, I even hope them un-sent or blocked. >> >> The patches include two -solutions-: >> >> Shit_A: >> workqueue: reset pool->node and unhash the pool when the node is >> offline >> update wq_numa when cpu_present_mask changed >> >> kernel/workqueue.c | 107 +++++++++++++++++++++++++++++++++++++++++------------ >> 1 file changed, 84 insertions(+), 23 deletions(-) >> >> >> Shit_B: >> workqueue: reset pool->node and unhash the pool when the node is >> offline >> workqueue: remove wq_numa_possible_cpumask >> workqueue: directly update attrs of pools when cpu hot[un]plug >> >> kernel/workqueue.c | 135 +++++++++++++++++++++++++++++++++++++++-------------- >> 1 file changed, 101 insertions(+), 34 deletions(-) >> >> >> Both patch1 of the both solutions are: reset pool->node and unhash the pool, >> it is suggested by TJ, I found it is a good leading-step for fixing the bug. >> >> The other patches are handling wq_numa_possible_cpumask where the solutions >> diverge. >> >> Solution_A uses present_mask rather than possible_cpumask. It adds >> wq_numa_notify_cpu_present_set/cleared() for notifications of >> the changes of cpu_present_mask. But the notifications are un-existed >> right now, so I fake one (wq_numa_check_present_cpumask_changes()) >> to imitate them. I hope the memory people add a real one. >> >> Solution_B uses online_mask rather than possible_cpumask. >> this solution remove more coupling between numa_code and workqueue, >> it just depends on cpumask_of_node(node). >> >> Patch2_of_Solution_B removes the wq_numa_possible_cpumask and add >> overhead when cpu hot[un]plug, Patch3 reduce this overhead. >> >> Thanks, >> Lai >> >> >> Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> Cc: Tejun Heo <tj@kernel.org> >> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> Cc: "Gu, Zheng" <guz.fnst@cn.fujitsu.com> >> Cc: tangchen <tangchen@cn.fujitsu.com> >> Cc: Hiroyuki KAMEZAWA <kamezawa.hiroyu@jp.fujitsu.com> >> > > > . >
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