lkml.org 
[lkml]   [2018]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Will the recent memory leak fixes be backported to longterm kernels?
On Fri 02-11-18 17:25:58, Roman Gushchin wrote:
> On Fri, Nov 02, 2018 at 05:51:47PM +0100, Michal Hocko wrote:
> > On Fri 02-11-18 16:22:41, Roman Gushchin wrote:
[...]
> > > 2) We do forget to scan the last page in the LRU list. So if we ended up with
> > > 1-page long LRU, it can stay there basically forever.
> >
> > Why
> > /*
> > * If the cgroup's already been deleted, make sure to
> > * scrape out the remaining cache.
> > */
> > if (!scan && !mem_cgroup_online(memcg))
> > scan = min(size, SWAP_CLUSTER_MAX);
> >
> > in get_scan_count doesn't work for that case?
>
> No, it doesn't. Let's look at the whole picture:
>
> size = lruvec_lru_size(lruvec, lru, sc->reclaim_idx);
> scan = size >> sc->priority;
> /*
> * If the cgroup's already been deleted, make sure to
> * scrape out the remaining cache.
> */
> if (!scan && !mem_cgroup_online(memcg))
> scan = min(size, SWAP_CLUSTER_MAX);
>
> If size == 1, scan == 0 => scan = min(1, 32) == 1.
> And after proportional adjustment we'll have 0.

My friday brain hurst when looking at this but if it doesn't work as
advertized then it should be fixed. I do not see any of your patches to
touch this logic so how come it would work after them applied?
--
Michal Hocko
SUSE Labs

\
 
 \ /
  Last update: 2018-11-02 18:48    [W:0.106 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site