Messages in this thread | | | From | Shakeel Butt <> | Date | Mon, 13 Jan 2020 10:38:45 -0800 | Subject | Re: [bug report] resctrl high memory comsumption |
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On Wed, Jan 8, 2020 at 1:54 PM Reinette Chatre <reinette.chatre@intel.com> wrote: > > Hi Fenghua, > > On 1/8/2020 1:42 PM, Fenghua Yu wrote: > > On Wed, Jan 08, 2020 at 12:42:17PM -0800, Reinette Chatre wrote: > >> Hi Fenghua, > >> On 1/8/2020 12:23 PM, Fenghua Yu wrote: > >>> On Wed, Jan 08, 2020 at 09:07:41AM -0800, Shakeel Butt wrote: > >>>> Recently we had a bug in the system software writing the same pids to > >>>> the tasks file of resctrl group multiple times. The resctrl code > >>> Subject: [RFC PATCH] x86/resctrl: Fix redundant task movements > >> I think your fix would address this specific use case but a slightly > >> different use case will still encounter the problem of high memory > >> consumption. If for example, sleeping tasks are moved (many times) > >> between resource or monitoring groups then their task_works queue would > >> just keep growing. It seems that a call to task_work_cancel() before > >> adding a new work item should address all these cases? > > > > The checking code in this patch is also helpful to avoid redundant > > task move preparation (kzalloc(), task_work_add(), etc) in the same > > rdtgroup. > > Indeed. > > > > > How about adding both the checking code and task_work_cancel()? > > That does sound good to me. >
Hi Fenghua, any updates here?
> There is something in the current implementation that I would appreciate > your feedback on: Currently the task's closid and rmid are initialized > _after_ the call to task_work_add() succeeds. Should these not be > initialized before the call to task_work_add()? >
This seems like a potential race.
thanks, Shakeel
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