lkml.org 
[lkml]   [2013]   [Jun]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v5] Soft limit rework
On Tue, Jun 18, 2013 at 02:09:39PM +0200, Michal Hocko wrote:
> base is mmotm-2013-05-09-15-57
> baserebase is mmotm-2013-06-05-17-24-63 + patches from the current mmots
> without slab shrinkers patchset.
> reworkrebase all patches 8 applied on top of baserebase
>
> * No-limit
> User
> base: min: 1164.94 max: 1169.75 avg: 1168.31 std: 1.57 runs: 6
> baserebase: min: 1169.46 [100.4%] max: 1176.07 [100.5%] avg: 1172.49 [100.4%] std: 2.38 runs: 6
> reworkrebase: min: 1172.58 [100.7%] max: 1177.43 [100.7%] avg: 1175.53 [100.6%] std: 1.91 runs: 6
> System
> base: min: 242.55 max: 245.36 avg: 243.92 std: 1.17 runs: 6
> baserebase: min: 235.36 [97.0%] max: 238.52 [97.2%] avg: 236.70 [97.0%] std: 1.04 runs: 6
> reworkrebase: min: 236.21 [97.4%] max: 239.46 [97.6%] avg: 237.55 [97.4%] std: 1.05 runs: 6
> Elapsed
> base: min: 596.81 max: 620.04 avg: 605.52 std: 7.56 runs: 6
> baserebase: min: 666.45 [111.7%] max: 710.89 [114.7%] avg: 690.62 [114.1%] std: 13.85 runs: 6
> reworkrebase: min: 664.05 [111.3%] max: 701.06 [113.1%] avg: 689.29 [113.8%] std: 12.36 runs: 6
>
> Elapsed time regressed by 13% wrt. base but it seems that this came from
> baserebase which regressed by the same amount.
>

boo-urns

> Page fault statistics tell us at least part of the story:
> Minor
> base: min: 35941845.00 max: 36029788.00 avg: 35986860.17 std: 28288.66 runs: 6
> baserebase: min: 35852414.00 [99.8%] max: 35899605.00 [99.6%] avg: 35874906.83 [99.7%] std: 18722.59 runs: 6
> reworkrebase: min: 35538346.00 [98.9%] max: 35584907.00 [98.8%] avg: 35562362.17 [98.8%] std: 18921.74 runs: 6
> Major
> base: min: 25390.00 max: 33132.00 avg: 29961.83 std: 2476.58 runs: 6
> baserebase: min: 34224.00 [134.8%] max: 45674.00 [137.9%] avg: 41556.83 [138.7%] std: 3595.39 runs: 6
> reworkrebase: min: 277.00 [1.1%] max: 480.00 [1.4%] avg: 384.67 [1.3%] std: 74.67 runs: 6

Can you try this monolithic patch please?

diff --git a/mm/vmscan.c b/mm/vmscan.c
index fe73724..f677780 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1477,25 +1477,11 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
* as there is no guarantee the dirtying process is throttled in the
* same way balance_dirty_pages() manages.
*
- * This scales the number of dirty pages that must be under writeback
- * before a zone gets flagged ZONE_WRITEBACK. It is a simple backoff
- * function that has the most effect in the range DEF_PRIORITY to
- * DEF_PRIORITY-2 which is the priority reclaim is considered to be
- * in trouble and reclaim is considered to be in trouble.
- *
- * DEF_PRIORITY 100% isolated pages must be PageWriteback to throttle
- * DEF_PRIORITY-1 50% must be PageWriteback
- * DEF_PRIORITY-2 25% must be PageWriteback, kswapd in trouble
- * ...
- * DEF_PRIORITY-6 For SWAP_CLUSTER_MAX isolated pages, throttle if any
- * isolated page is PageWriteback
- *
* Once a zone is flagged ZONE_WRITEBACK, kswapd will count the number
* of pages under pages flagged for immediate reclaim and stall if any
* are encountered in the nr_immediate check below.
*/
- if (nr_writeback && nr_writeback >=
- (nr_taken >> (DEF_PRIORITY - sc->priority)))
+ if (nr_writeback && nr_writeback == nr_taken)
zone_set_flag(zone, ZONE_WRITEBACK);

/*
@@ -2382,12 +2368,14 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
struct zone *zone;
unsigned long writeback_threshold;
bool aborted_reclaim;
+ int min_scan_priority = 1;

delayacct_freepages_start();

if (global_reclaim(sc))
count_vm_event(ALLOCSTALL);

+rescan:
do {
vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
sc->priority);
@@ -2442,7 +2430,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
WB_REASON_TRY_TO_FREE_PAGES);
sc->may_writepage = 1;
}
- } while (--sc->priority >= 0);
+ } while (--sc->priority >= min_scan_priority);

out:
delayacct_freepages_end();
@@ -2466,6 +2454,12 @@ out:
if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc))
return 1;

+ /* If the page allocator is going to consider OOM, rescan at priority 0 */
+ if (min_scan_priority) {
+ min_scan_priority = 0;
+ goto rescan;
+ }
+
return 0;
}


\
 
 \ /
  Last update: 2013-06-20 14:01    [W:0.251 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site