Messages in this thread Patch in this message | | | Date | Mon, 23 May 2011 08:12:50 +0900 | Subject | Re: Kernel falls apart under light memory pressure (i.e. linking vmlinux) | From | Minchan Kim <> |
| |
On Sun, May 22, 2011 at 9:22 PM, Andrew Lutomirski <luto@mit.edu> wrote: > On Sat, May 21, 2011 at 10:44 AM, Minchan Kim <minchan.kim@gmail.com> wrote: >> I would like to confirm this problem. >> Could you show the diff of 2.6.38.6 with current your 2.6.38.6 + alpha? >> (ie, I would like to know that what patches you add up on vanilla >> 2.6.38.6 to reproduce this problem) >> I believe you added my crap below patch. Right? >> >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index 292582c..69d317e 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -311,7 +311,8 @@ static void set_reclaim_mode(int priority, struct >> scan_control *sc, >> */ >> if (sc->order > PAGE_ALLOC_COSTLY_ORDER) >> sc->reclaim_mode |= syncmode; >> - else if (sc->order && priority < DEF_PRIORITY - 2) >> + else if ((sc->order && priority < DEF_PRIORITY - 2) || >> + prioiry <= DEF_PRIORITY / 3) >> sc->reclaim_mode |= syncmode; >> else >> sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC; >> @@ -1349,10 +1350,6 @@ static inline bool >> should_reclaim_stall(unsigned long nr_taken, >> if (current_is_kswapd()) >> return false; >> >> - /* Only stall on lumpy reclaim */ >> - if (sc->reclaim_mode & RECLAIM_MODE_SINGLE) >> - return false; >> - > > Bah. It's this last hunk. Without this I can't reproduce the oops. > With this hunk, the reset_reclaim_mode doesn't work and > shrink_page_list is incorrectly called twice.
OMG! I should have said more clearly to you. Above my patch is totally _crap_. I thought you have experimented test without above crap patch. :( Sorry for consuming time of many mm guys. My apologies.
I want to resolve your original problem(ie, hang) before digging the OOM problem.
> > So we're back to the original problem...
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; } -- 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/
| |