* [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages @ 2015-08-04 10:40 ` Jaewon Kim 0 siblings, 0 replies; 10+ messages in thread From: Jaewon Kim @ 2015-08-04 10:40 UTC (permalink / raw) To: akpm; +Cc: mgorman, minchan, linux-mm, linux-kernel, jaewon31.kim, Jaewon Kim reclaim_clean_pages_from_list() assumes that shrink_page_list() returns number of pages removed from the candidate list. But shrink_page_list() puts back mlocked pages without passing it to caller and without counting as nr_reclaimed. This incurrs increasing nr_isolated. To fix this, this patch changes shrink_page_list() to pass unevictable pages back to caller. Caller will take care those pages. Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> --- Changes since v1 1/ changed subject from vmscan: reclaim_clean_pages_from_list() must count mlocked pages 2/ changed to return unevictable pages rather than returning the number of unevictable pages mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 5e8eadd..a4b2d07 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1157,7 +1157,7 @@ cull_mlocked: if (PageSwapCache(page)) try_to_free_swap(page); unlock_page(page); - putback_lru_page(page); + list_add(&page->lru, &ret_pages); continue; activate_locked: -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages @ 2015-08-04 10:40 ` Jaewon Kim 0 siblings, 0 replies; 10+ messages in thread From: Jaewon Kim @ 2015-08-04 10:40 UTC (permalink / raw) To: akpm; +Cc: mgorman, minchan, linux-mm, linux-kernel, jaewon31.kim, Jaewon Kim reclaim_clean_pages_from_list() assumes that shrink_page_list() returns number of pages removed from the candidate list. But shrink_page_list() puts back mlocked pages without passing it to caller and without counting as nr_reclaimed. This incurrs increasing nr_isolated. To fix this, this patch changes shrink_page_list() to pass unevictable pages back to caller. Caller will take care those pages. Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> --- Changes since v1 1/ changed subject from vmscan: reclaim_clean_pages_from_list() must count mlocked pages 2/ changed to return unevictable pages rather than returning the number of unevictable pages mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 5e8eadd..a4b2d07 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1157,7 +1157,7 @@ cull_mlocked: if (PageSwapCache(page)) try_to_free_swap(page); unlock_page(page); - putback_lru_page(page); + list_add(&page->lru, &ret_pages); continue; activate_locked: -- 1.9.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages 2015-08-04 10:40 ` Jaewon Kim @ 2015-08-04 22:09 ` Andrew Morton -1 siblings, 0 replies; 10+ messages in thread From: Andrew Morton @ 2015-08-04 22:09 UTC (permalink / raw) To: Jaewon Kim; +Cc: mgorman, minchan, linux-mm, linux-kernel, jaewon31.kim On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: > reclaim_clean_pages_from_list() assumes that shrink_page_list() returns > number of pages removed from the candidate list. But shrink_page_list() > puts back mlocked pages without passing it to caller and without > counting as nr_reclaimed. This incurrs increasing nr_isolated. > To fix this, this patch changes shrink_page_list() to pass unevictable > pages back to caller. Caller will take care those pages. > > .. > > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1157,7 +1157,7 @@ cull_mlocked: > if (PageSwapCache(page)) > try_to_free_swap(page); > unlock_page(page); > - putback_lru_page(page); > + list_add(&page->lru, &ret_pages); > continue; > > activate_locked: Is this going to cause a whole bunch of mlocked pages to be migrated whereas in current kernels they stay where they are? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages @ 2015-08-04 22:09 ` Andrew Morton 0 siblings, 0 replies; 10+ messages in thread From: Andrew Morton @ 2015-08-04 22:09 UTC (permalink / raw) To: Jaewon Kim; +Cc: mgorman, minchan, linux-mm, linux-kernel, jaewon31.kim On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: > reclaim_clean_pages_from_list() assumes that shrink_page_list() returns > number of pages removed from the candidate list. But shrink_page_list() > puts back mlocked pages without passing it to caller and without > counting as nr_reclaimed. This incurrs increasing nr_isolated. > To fix this, this patch changes shrink_page_list() to pass unevictable > pages back to caller. Caller will take care those pages. > > .. > > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1157,7 +1157,7 @@ cull_mlocked: > if (PageSwapCache(page)) > try_to_free_swap(page); > unlock_page(page); > - putback_lru_page(page); > + list_add(&page->lru, &ret_pages); > continue; > > activate_locked: Is this going to cause a whole bunch of mlocked pages to be migrated whereas in current kernels they stay where they are? ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages 2015-08-04 22:09 ` Andrew Morton @ 2015-08-04 23:31 ` Minchan Kim -1 siblings, 0 replies; 10+ messages in thread From: Minchan Kim @ 2015-08-04 23:31 UTC (permalink / raw) To: Andrew Morton; +Cc: Jaewon Kim, mgorman, linux-mm, linux-kernel, jaewon31.kim Hello, On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: > On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: > > > reclaim_clean_pages_from_list() assumes that shrink_page_list() returns > > number of pages removed from the candidate list. But shrink_page_list() > > puts back mlocked pages without passing it to caller and without > > counting as nr_reclaimed. This incurrs increasing nr_isolated. > > To fix this, this patch changes shrink_page_list() to pass unevictable > > pages back to caller. Caller will take care those pages. > > > > .. > > > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1157,7 +1157,7 @@ cull_mlocked: > > if (PageSwapCache(page)) > > try_to_free_swap(page); > > unlock_page(page); > > - putback_lru_page(page); > > + list_add(&page->lru, &ret_pages); > > continue; > > > > activate_locked: > > Is this going to cause a whole bunch of mlocked pages to be migrated > whereas in current kernels they stay where they are? > It fixes two issues. 1. With unevictable page, cma_alloc will be successful. Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. 2. fix leaking of NR_ISOLATED counter of vmstat With it, too_many_isolated works. Otherwise, it could make hang until the process get SIGKILL. So, I think it's stable material. Acked-by: Minchan Kim <minchan@kernel.org> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages @ 2015-08-04 23:31 ` Minchan Kim 0 siblings, 0 replies; 10+ messages in thread From: Minchan Kim @ 2015-08-04 23:31 UTC (permalink / raw) To: Andrew Morton; +Cc: Jaewon Kim, mgorman, linux-mm, linux-kernel, jaewon31.kim Hello, On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: > On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: > > > reclaim_clean_pages_from_list() assumes that shrink_page_list() returns > > number of pages removed from the candidate list. But shrink_page_list() > > puts back mlocked pages without passing it to caller and without > > counting as nr_reclaimed. This incurrs increasing nr_isolated. > > To fix this, this patch changes shrink_page_list() to pass unevictable > > pages back to caller. Caller will take care those pages. > > > > .. > > > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1157,7 +1157,7 @@ cull_mlocked: > > if (PageSwapCache(page)) > > try_to_free_swap(page); > > unlock_page(page); > > - putback_lru_page(page); > > + list_add(&page->lru, &ret_pages); > > continue; > > > > activate_locked: > > Is this going to cause a whole bunch of mlocked pages to be migrated > whereas in current kernels they stay where they are? > It fixes two issues. 1. With unevictable page, cma_alloc will be successful. Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. 2. fix leaking of NR_ISOLATED counter of vmstat With it, too_many_isolated works. Otherwise, it could make hang until the process get SIGKILL. So, I think it's stable material. Acked-by: Minchan Kim <minchan@kernel.org> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages 2015-08-04 23:31 ` Minchan Kim @ 2015-08-05 0:52 ` Jaewon Kim -1 siblings, 0 replies; 10+ messages in thread From: Jaewon Kim @ 2015-08-05 0:52 UTC (permalink / raw) To: Minchan Kim, Andrew Morton; +Cc: mgorman, linux-mm, linux-kernel, jaewon31.kim On 2015e?? 08i?? 05i? 1/4 08:31, Minchan Kim wrote: > Hello, > > On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: >> On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: >> >>> reclaim_clean_pages_from_list() assumes that shrink_page_list() returns >>> number of pages removed from the candidate list. But shrink_page_list() >>> puts back mlocked pages without passing it to caller and without >>> counting as nr_reclaimed. This incurrs increasing nr_isolated. >>> To fix this, this patch changes shrink_page_list() to pass unevictable >>> pages back to caller. Caller will take care those pages. >>> >>> .. >>> >>> --- a/mm/vmscan.c >>> +++ b/mm/vmscan.c >>> @@ -1157,7 +1157,7 @@ cull_mlocked: >>> if (PageSwapCache(page)) >>> try_to_free_swap(page); >>> unlock_page(page); >>> - putback_lru_page(page); >>> + list_add(&page->lru, &ret_pages); >>> continue; >>> >>> activate_locked: >> >> Is this going to cause a whole bunch of mlocked pages to be migrated >> whereas in current kernels they stay where they are? >> > > It fixes two issues. > > 1. With unevictable page, cma_alloc will be successful. > > Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. > > 2. fix leaking of NR_ISOLATED counter of vmstat > > With it, too_many_isolated works. Otherwise, it could make hang until > the process get SIGKILL. > > So, I think it's stable material. > > Acked-by: Minchan Kim <minchan@kernel.org> > > > Hello Traditional shrink_inactive_list will put back the unevictable pages as it does through putback_inactive_pages. However as Minchan Kim said, cma_alloc will be more successful by migrating unevictable pages. In current kernel, I think, cma_alloc is already trying to migrate unevictable pages except clean page cache. This patch will allow clean page cache also to be migrated in cma_alloc. Thank you -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages @ 2015-08-05 0:52 ` Jaewon Kim 0 siblings, 0 replies; 10+ messages in thread From: Jaewon Kim @ 2015-08-05 0:52 UTC (permalink / raw) To: Minchan Kim, Andrew Morton; +Cc: mgorman, linux-mm, linux-kernel, jaewon31.kim On 2015년 08월 05일 08:31, Minchan Kim wrote: > Hello, > > On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: >> On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: >> >>> reclaim_clean_pages_from_list() assumes that shrink_page_list() returns >>> number of pages removed from the candidate list. But shrink_page_list() >>> puts back mlocked pages without passing it to caller and without >>> counting as nr_reclaimed. This incurrs increasing nr_isolated. >>> To fix this, this patch changes shrink_page_list() to pass unevictable >>> pages back to caller. Caller will take care those pages. >>> >>> .. >>> >>> --- a/mm/vmscan.c >>> +++ b/mm/vmscan.c >>> @@ -1157,7 +1157,7 @@ cull_mlocked: >>> if (PageSwapCache(page)) >>> try_to_free_swap(page); >>> unlock_page(page); >>> - putback_lru_page(page); >>> + list_add(&page->lru, &ret_pages); >>> continue; >>> >>> activate_locked: >> >> Is this going to cause a whole bunch of mlocked pages to be migrated >> whereas in current kernels they stay where they are? >> > > It fixes two issues. > > 1. With unevictable page, cma_alloc will be successful. > > Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. > > 2. fix leaking of NR_ISOLATED counter of vmstat > > With it, too_many_isolated works. Otherwise, it could make hang until > the process get SIGKILL. > > So, I think it's stable material. > > Acked-by: Minchan Kim <minchan@kernel.org> > > > Hello Traditional shrink_inactive_list will put back the unevictable pages as it does through putback_inactive_pages. However as Minchan Kim said, cma_alloc will be more successful by migrating unevictable pages. In current kernel, I think, cma_alloc is already trying to migrate unevictable pages except clean page cache. This patch will allow clean page cache also to be migrated in cma_alloc. Thank you ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages 2015-08-05 0:52 ` Jaewon Kim @ 2015-08-06 12:21 ` Vlastimil Babka -1 siblings, 0 replies; 10+ messages in thread From: Vlastimil Babka @ 2015-08-06 12:21 UTC (permalink / raw) To: Jaewon Kim, Minchan Kim, Andrew Morton Cc: mgorman, linux-mm, linux-kernel, jaewon31.kim On 08/05/2015 02:52 AM, Jaewon Kim wrote: > > > On 2015e?? 08i?? 05i? 1/4 08:31, Minchan Kim wrote: >> Hello, >> >> On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: >>> On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: >>> >>>> reclaim_clean_pages_from_list() assumes that shrink_page_list() returns >>>> number of pages removed from the candidate list. But shrink_page_list() >>>> puts back mlocked pages without passing it to caller and without >>>> counting as nr_reclaimed. This incurrs increasing nr_isolated. >>>> To fix this, this patch changes shrink_page_list() to pass unevictable >>>> pages back to caller. Caller will take care those pages. >>>> >>>> .. >>>> >>>> --- a/mm/vmscan.c >>>> +++ b/mm/vmscan.c >>>> @@ -1157,7 +1157,7 @@ cull_mlocked: >>>> if (PageSwapCache(page)) >>>> try_to_free_swap(page); >>>> unlock_page(page); >>>> - putback_lru_page(page); >>>> + list_add(&page->lru, &ret_pages); >>>> continue; >>>> >>>> activate_locked: >>> >>> Is this going to cause a whole bunch of mlocked pages to be migrated >>> whereas in current kernels they stay where they are? The only user that will see the change wrt migration is __alloc_contig_migrate_range() which is explicit about isolating mlocked page for migration (isolate_migratepages_range() calls isolate_migratepages_block() with ISOLATE_UNEVICTABLE). So this will make the migration work for clean page cache too. >> >> >> It fixes two issues. >> >> 1. With unevictable page, cma_alloc will be successful. >> >> Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. >> >> 2. fix leaking of NR_ISOLATED counter of vmstat >> >> With it, too_many_isolated works. Otherwise, it could make hang until >> the process get SIGKILL. This should be more explicit in the changelog. The first issue is not mentioned at all. The second is not clear from the description. >> >> So, I think it's stable material. >> >> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> >> >> > Hello > > Traditional shrink_inactive_list will put back the unevictable pages as it does through putback_inactive_pages. > However as Minchan Kim said, cma_alloc will be more successful by migrating unevictable pages. > In current kernel, I think, cma_alloc is already trying to migrate unevictable pages except clean page cache. > This patch will allow clean page cache also to be migrated in cma_alloc. > > Thank you > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages @ 2015-08-06 12:21 ` Vlastimil Babka 0 siblings, 0 replies; 10+ messages in thread From: Vlastimil Babka @ 2015-08-06 12:21 UTC (permalink / raw) To: Jaewon Kim, Minchan Kim, Andrew Morton Cc: mgorman, linux-mm, linux-kernel, jaewon31.kim On 08/05/2015 02:52 AM, Jaewon Kim wrote: > > > On 2015년 08월 05일 08:31, Minchan Kim wrote: >> Hello, >> >> On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: >>> On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@samsung.com> wrote: >>> >>>> reclaim_clean_pages_from_list() assumes that shrink_page_list() returns >>>> number of pages removed from the candidate list. But shrink_page_list() >>>> puts back mlocked pages without passing it to caller and without >>>> counting as nr_reclaimed. This incurrs increasing nr_isolated. >>>> To fix this, this patch changes shrink_page_list() to pass unevictable >>>> pages back to caller. Caller will take care those pages. >>>> >>>> .. >>>> >>>> --- a/mm/vmscan.c >>>> +++ b/mm/vmscan.c >>>> @@ -1157,7 +1157,7 @@ cull_mlocked: >>>> if (PageSwapCache(page)) >>>> try_to_free_swap(page); >>>> unlock_page(page); >>>> - putback_lru_page(page); >>>> + list_add(&page->lru, &ret_pages); >>>> continue; >>>> >>>> activate_locked: >>> >>> Is this going to cause a whole bunch of mlocked pages to be migrated >>> whereas in current kernels they stay where they are? The only user that will see the change wrt migration is __alloc_contig_migrate_range() which is explicit about isolating mlocked page for migration (isolate_migratepages_range() calls isolate_migratepages_block() with ISOLATE_UNEVICTABLE). So this will make the migration work for clean page cache too. >> >> >> It fixes two issues. >> >> 1. With unevictable page, cma_alloc will be successful. >> >> Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. >> >> 2. fix leaking of NR_ISOLATED counter of vmstat >> >> With it, too_many_isolated works. Otherwise, it could make hang until >> the process get SIGKILL. This should be more explicit in the changelog. The first issue is not mentioned at all. The second is not clear from the description. >> >> So, I think it's stable material. >> >> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> >> >> > Hello > > Traditional shrink_inactive_list will put back the unevictable pages as it does through putback_inactive_pages. > However as Minchan Kim said, cma_alloc will be more successful by migrating unevictable pages. > In current kernel, I think, cma_alloc is already trying to migrate unevictable pages except clean page cache. > This patch will allow clean page cache also to be migrated in cma_alloc. > > Thank you > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> > ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2015-08-06 12:21 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-08-04 10:40 [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback unevictable pages Jaewon Kim 2015-08-04 10:40 ` Jaewon Kim 2015-08-04 22:09 ` Andrew Morton 2015-08-04 22:09 ` Andrew Morton 2015-08-04 23:31 ` Minchan Kim 2015-08-04 23:31 ` Minchan Kim 2015-08-05 0:52 ` Jaewon Kim 2015-08-05 0:52 ` Jaewon Kim 2015-08-06 12:21 ` Vlastimil Babka 2015-08-06 12:21 ` Vlastimil Babka
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