Messages in this thread | | | Date | Tue, 28 Feb 2012 14:37:38 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 2/9] memcg: add dirty page accounting infrastructure |
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On Tue, 28 Feb 2012 22:00:24 +0800 Fengguang Wu <fengguang.wu@intel.com> wrote:
> From: Greg Thelen <gthelen@google.com> > > Add memcg routines to count dirty, writeback, and unstable_NFS pages. > These routines are not yet used by the kernel to count such pages. A > later change adds kernel calls to these new routines. > > As inode pages are marked dirty, if the dirtied page's cgroup differs > from the inode's cgroup, then mark the inode shared across several > cgroup. > > ... > > @@ -1885,6 +1888,44 @@ void mem_cgroup_update_page_stat(struct > ClearPageCgroupFileMapped(pc); > idx = MEM_CGROUP_STAT_FILE_MAPPED; > break; > + > + case MEMCG_NR_FILE_DIRTY: > + /* Use Test{Set,Clear} to only un/charge the memcg once. */ > + if (val > 0) { > + if (TestSetPageCgroupFileDirty(pc)) > + val = 0; > + } else { > + if (!TestClearPageCgroupFileDirty(pc)) > + val = 0; > + }
Made me scratch my head for a while, but I see now that the `val' arg to (the undocumented) mem_cgroup_update_page_stat() can only ever have the values 1 or -1. I hope.
> > ... >
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