Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1409863 > unrolled thread

Re: [RFC 03/13] mm, page_alloc: don't retry initial attempt in slowpath

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [RFC 03/13] mm, page_alloc: don't retry initial attempt in  slowpath Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-05-31 08:30 +0200
    Re: [RFC 03/13] mm, page_alloc: don't retry initial attempt in  slowpath Vlastimil Babka <vbabka@suse.cz> - 2016-05-31 14:10 +0200

#1409863 — Re: [RFC 03/13] mm, page_alloc: don't retry initial attempt in slowpath

On Tue, May 10, 2016 at 09:35:53AM +0200, Vlastimil Babka wrote:
> After __alloc_pages_slowpath() sets up new alloc_flags and wakes up kswapd, it
> first tries get_page_from_freelist() with the new alloc_flags, as it may
> succeed e.g. due to using min watermark instead of low watermark. This attempt
> does not have to be retried on each loop, since direct reclaim, direct
> compaction and oom call get_page_from_freelist() themselves.

Hmm... there is a corner case. If did_some_progress is 0 or compaction
is deferred, get_page_from_freelist() isn't called. But, we can
succeed to allocate memory since there is a kswapd that reclaims
memory in background.

Thanks.

[toc] | [next] | [standalone]

#1410233

On 05/31/2016 08:25 AM, Joonsoo Kim wrote:
> On Tue, May 10, 2016 at 09:35:53AM +0200, Vlastimil Babka wrote:
>> After __alloc_pages_slowpath() sets up new alloc_flags and wakes up kswapd, it
>> first tries get_page_from_freelist() with the new alloc_flags, as it may
>> succeed e.g. due to using min watermark instead of low watermark. This attempt
>> does not have to be retried on each loop, since direct reclaim, direct
>> compaction and oom call get_page_from_freelist() themselves.
>
> Hmm... there is a corner case. If did_some_progress is 0 or compaction
> is deferred, get_page_from_freelist() isn't called. But, we can
> succeed to allocate memory since there is a kswapd that reclaims
> memory in background.

Hmm good point. I think the cleanest solution is to let 
__alloc_pages_direct_reclaim attempt regardless of did_some_progress.

> Thanks.
>

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web