Re: [PATCH][RFC] dirty balancing for cgroups
From: KAMEZAWA Hiroyuki <hidden>
Date: 2008-08-06 08:56:32
Also in:
lkml
Possibly related (same subject, not in this thread)
- 2008-08-18 · Re: [PATCH][RFC] dirty balancing for cgroups · KAMEZAWA Hiroyuki <hidden>
- 2008-08-14 · Re: [PATCH][RFC] dirty balancing for cgroups · Paul Menage <hidden>
- 2008-08-13 · Re: [PATCH][RFC] dirty balancing for cgroups · YAMAMOTO Takashi <hidden>
- 2008-08-06 · Re: [PATCH][RFC] dirty balancing for cgroups · YAMAMOTO Takashi <hidden>
- 2008-07-17 · Re: [PATCH][RFC] dirty balancing for cgroups · YAMAMOTO Takashi <hidden>
On Wed, 6 Aug 2008 17:20:46 +0900 (JST) yamamoto@valinux.co.jp (YAMAMOTO Takashi) wrote:
hi,quoted
On Fri, 11 Jul 2008 17:34:46 +0900 (JST) yamamoto@valinux.co.jp (YAMAMOTO Takashi) wrote:quoted
hi,quoted
quoted
my patch penalizes heavy-writer cgroups as task_dirty_limit does for heavy-writer tasks. i don't think that it's necessary to be tied to the memory subsystem because i merely want to group writers.Hmm, maybe what I need is different from this ;) Does not seem to be a help for memory reclaim under memcg.to implement what you need, i think that we need to keep track of the numbers of dirty-pages in each memory cgroups as a first step. do you agree?yes, I think so, now. may be not difficult but will add extra overhead ;( Sigh..the following is a patch to add the overhead. :) any comments?
Do you have some numbers ? ;) I like this because this seems very straightforward. thank you.
quoted hunk ↗ jump to hunk
@@ -485,7 +502,10 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, if (PageUnevictable(page) || (PageActive(page) && !active) || (!PageActive(page) && active)) { - __mem_cgroup_move_lists(pc, page_lru(page)); + if (try_lock_page_cgroup(page)) { + __mem_cgroup_move_lists(pc, page_lru(page)); + unlock_page_cgroup(page); + } continue; }
Hmm..ok, there will be new race between Dirty Bit and LRU bits.
quoted hunk ↗ jump to hunk
@@ -772,6 +792,38 @@ void mem_cgroup_end_migration(struct page *newpage) mem_cgroup_uncharge_page(newpage); } +void mem_cgroup_set_page_dirty(struct page *pg) +{ + struct page_cgroup *pc; + + lock_page_cgroup(pg); + pc = page_get_page_cgroup(pg); + if (pc != NULL && (pc->flags & PAGE_CGROUP_FLAG_DIRTY) == 0) { + struct mem_cgroup *mem = pc->mem_cgroup; + struct mem_cgroup_stat *stat = &mem->stat; + + pc->flags |= PAGE_CGROUP_FLAG_DIRTY; + __mem_cgroup_stat_add(stat, MEM_CGROUP_STAT_DIRTY, 1); + } + unlock_page_cgroup(pg); +} + +void mem_cgroup_clear_page_dirty(struct page *pg) +{ + struct page_cgroup *pc; + + lock_page_cgroup(pg); + pc = page_get_page_cgroup(pg); + if (pc != NULL && (pc->flags & PAGE_CGROUP_FLAG_DIRTY) != 0) { + struct mem_cgroup *mem = pc->mem_cgroup; + struct mem_cgroup_stat *stat = &mem->stat; + + pc->flags &= ~PAGE_CGROUP_FLAG_DIRTY; + __mem_cgroup_stat_add(stat, MEM_CGROUP_STAT_DIRTY, -1); + } + unlock_page_cgroup(pg); +} +
How about changing these to be
==
void mem_cgroup_test_set_page_dirty()
{
if (try_lock_page_cgroup(pg)) {
pc = page_get_page_cgroup(pg);
if (pc ......) {
}
unlock_page_cgroup(pg)
}
}
==
Off-topic: I wonder we can delete this "lock" in future.
Because page->page_cgroup is
1. attached at first use.(Obiously no race with set_dirty)
2. deleted at removal. (force_empty is problematic here..)
But, now, we need this lock.
Thanks,
-Kame
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