Messages in this thread | | | Date | Mon, 18 Jan 2010 11:25:10 +0900 | Subject | Re: [PATCH 2/3][v2] vmstat: add anon_scan_ratio field to zoneinfo | From | Minchan Kim <> |
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On Mon, Jan 18, 2010 at 11:16 AM, Rik van Riel <riel@redhat.com> wrote: > On 01/17/2010 09:10 PM, Minchan Kim wrote: > >> Absoultely right. I missed that. Thanks. >> get_scan_ratio used lru_lock to get reclaim_stat->recent_xxxx. >> But, it doesn't used lru_lock to get ap/fp. >> >> Is it intentional? I think you or Rik know it. :) >> I think if we want to get exact value, we have to use lru_lock until >> getting ap/fp. >> If it isn't, we don't need lru_lock when we get the >> reclaim_stat->recent_xxxx. >> >> What do you think about it? > > This is definately not intentional. > > Getting race conditions in this code could throw off the > statistics by a factor 2. I do not know how serious that > would be for the VM or whether (and how quickly) it would > self correct.
Okay. How about making patch to get exact ap/fp? Although it were not serious or fast recoverable, I think it would be better to protect lru_lock for consistency if lru_lock isn't big contention lock.
> > -- > All rights reversed. >
-- Kind regards, Minchan Kim -- 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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