On Sun, May 22, 2011 at 7:12 PM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote:
> Could you test below patch based on vanilla 2.6.38.6?
> The expect result is that system hang never should happen.
> I hope this is last test about hang.
>
> Thanks.
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 292582c..1663d24 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -231,8 +231,11 @@ unsigned long shrink_slab(struct shrink_control *shrink,
> if (scanned == 0)
> scanned = SWAP_CLUSTER_MAX;
>
> - if (!down_read_trylock(&shrinker_rwsem))
> - return 1; /* Assume we'll be able to shrink next time */
> + if (!down_read_trylock(&shrinker_rwsem)) {
> + /* Assume we'll be able to shrink next time */
> + ret = 1;
> + goto out;
> + }
>
> list_for_each_entry(shrinker, &shrinker_list, list) {
> unsigned long long delta;
> @@ -286,6 +289,8 @@ unsigned long shrink_slab(struct shrink_control *shrink,
> shrinker->nr += total_scan;
> }
> up_read(&shrinker_rwsem);
> +out:
> + cond_resched();
> return ret;
> }
>
> @@ -2331,7 +2336,7 @@ static bool sleeping_prematurely(pg_data_t
> *pgdat, int order, long remaining,
> * must be balanced
> */
> if (order)
> - return pgdat_balanced(pgdat, balanced, classzone_idx);
> + return !pgdat_balanced(pgdat, balanced, classzone_idx);
> else
> return !all_zones_ok;
> }
So far with this patch I can't reproduce the hang or the bogus OOM.
To be completely clear, I have COMPACTION, MIGRATION, and THP off, I'm
running 2.6.38.6, and I have exactly two patches applied. One is the
attached patch and the other is a the fpu.ko/aesni_intel.ko merger
which I need to get dracut to boot my box.
For fun, I also upgraded to 8GB of RAM and it still works.
--Andy
>
> --
> Kind regards,
> Minchan Kim
>
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minchan-patch-v3.patch
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