Messages in this thread | | | Date | Thu, 3 Dec 2009 10:52:29 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 22/24] HWPOISON: add memory cgroup filter |
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On Wed, 2 Dec 2009 20:58:42 +0800 Wu Fengguang <fengguang.wu@intel.com> wrote:
> On Wed, Dec 02, 2009 at 08:44:46PM +0800, Andi Kleen wrote: > > > > > > +static int hwpoison_filter_task(struct page *p) > > > +{ > > > > Can we make that ifdef instead of depends on ? > > Sure. Here is the updated patch. > > --- > HWPOISON: add memory cgroup filter > > The hwpoison test suite need to inject hwpoison to a collection of > selected task pages, and must not touch pages not owned by them and > thus kill important system processes such as init. (But it's OK to > mis-hwpoison free/unowned pages as well as shared clean pages. > Mis-hwpoison of shared dirty pages will kill all tasks, so the test > suite will target all or non of such tasks in the first place.) > > The memory cgroup serves this purpose well. We can put the target > processes under the control of a memory cgroup, and tell the hwpoison > injection code to only kill pages associated with some active memory > cgroup. > > The prerequisite for doing hwpoison stress tests with mem_cgroup is, > the mem_cgroup code tracks task pages _accurately_ (unless page is > locked). Which we believe is/should be true. > > The benifits are simplification of hwpoison injector code. Also the > mem_cgroup code will automatically be tested by hwpoison test cases. > > The alternative interfaces pin-pfn/unpin-pfn can also delegate the > (process and page flags) filtering functions reliably to user space. > However prototype implementation shows that this scheme adds more > complexity than we wanted. > > CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > CC: Hugh Dickins <hugh.dickins@tiscali.co.uk> > CC: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> > CC: Balbir Singh <balbir@linux.vnet.ibm.com> > CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > CC: Li Zefan <lizf@cn.fujitsu.com> > CC: Paul Menage <menage@google.com> > CC: Nick Piggin <npiggin@suse.de> > CC: Andi Kleen <andi@firstfloor.org> > Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> > --- > mm/Kconfig | 2 +- > mm/hwpoison-inject.c | 7 +++++++ > mm/internal.h | 1 + > mm/memory-failure.c | 28 ++++++++++++++++++++++++++++ > 4 files changed, 37 insertions(+), 1 deletion(-) > > --- linux-mm.orig/mm/memory-failure.c 2009-12-01 09:56:06.000000000 +0800 > +++ linux-mm/mm/memory-failure.c 2009-12-02 20:56:55.000000000 +0800 > @@ -96,6 +96,31 @@ static int hwpoison_filter_flags(struct > return -EINVAL; > } > > +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP > +u32 hwpoison_filter_memcg; > +static int hwpoison_filter_task(struct page *p) > +{ > + struct mem_cgroup *mem; > + struct cgroup_subsys_state *css; > + > + if (!hwpoison_filter_memcg) > + return 0; > + > + mem = try_get_mem_cgroup_from_page(p); > + if (!mem) > + return -EINVAL; > + > + css = mem_cgroup_css(mem); > + if (!css) > + return -EINVAL;
> + > + css_put(css); > + return 0; > +}
Hmm..can you adds comment ? What does this function is for ?
Is this more meaningful than PageLRU(page) etc..?
Thanks, -Kame
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