Messages in this thread | | | Date | Thu, 26 Feb 2009 16:39:54 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 0/4] cpuset: cleanups and fixes |
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On Thu, 26 Feb 2009 15:02:15 +0800 Li Zefan <lizf@cn.fujitsu.com> wrote:
> This patchset mainly simplifies update_tasks_nodemask() and makes it > return void (won't fail), thus fix a case that writing to cpuset.mems > returns -ENOMEM but its mems_allowed has been changed. > > [PATCH 1/4] cgroups: add 'data' field to struct cgroup_scanner > [PATCH 2/4] cpuset: rewrite update_tasks_nodemask() > [PATCH 3/4] cpuset: avoid changing cpuset's mems when errno returned > [PATCH 4/4] cpuset: remove struct cpuset_hotplug_scanner > Thank you. I think there is no problematic in your patch.
After reading your patch, I wonder we can improve this migration by filter for cgroup_scan_tasks().
Assume a task with tons of threads in a cgroup and - change nodemask - migrate=1
Under current implemntation, cpuset_migrate_mm=>do_migrate_mm is called per threads. This implies there will be big overhead, useless scanning of page tables.
Can we add some checks as "Is this mm already migrated ?", anywhere ? (we may need to add some another array, again...)
Thanks, -Kame
> --- > include/linux/cgroup.h | 1 > kernel/cpuset.c | 151 +++++++++++++++++++------------------------------ > 2 files changed, 62 insertions(+), 90 deletions(-) > --- > > Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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