Messages in this thread | | | Date | Sat, 05 Jul 2008 11:11:10 +0530 | From | Balbir Singh <> | Subject | Re: [PATCH] memcg: handle shmem's swap cache (Was 2.6.26-rc8-mm1 |
| |
KAMEZAWA Hiroyuki wrote: > My swapcache accounting under memcg patch failed to catch tmpfs(shmem)'s one. > Can I test this under -mm tree ? > (If -mm is busy, I'm not in hurry.) > This patch works well in my box. > = > SwapCache handling fix. > > shmem's swapcache behavior is a little different from anonymous's one and > memcg failed to handle it. This patch tries to fix it. > > After this: > > Any page marked as SwapCache is not uncharged. (delelte_from_swap_cache() > delete the SwapCache flag.) > > To check a shmem-page-cache is alive or not we use > page->mapping && !PageAnon(page) instead of > pc->flags & PAGE_CGROUP_FLAG_CACHE. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Though I am not opposed to this, I do sit up and think if keeping the reference count around could avoid this complexity and from my point, the maintenance overhead of this logic/code (I fear there might be more special cases :( )
The trade-off is complexity versus the overhead of reference counting.
-- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL
| |