Re: [PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-26 Thread Jan Kara
On Tue 26-09-17 13:54:23, Michal Hocko wrote: > On Tue 26-09-17 19:45:45, Yafang Shao wrote: > > >> > To be honest I am not entirely sure this is worth the code and the > > >> > future maintenance burden. > > >> I'm not sure if this code is a burden for the future maintenance, but > > >> I think th

Re: [PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-26 Thread Michal Hocko
On Tue 26-09-17 19:45:45, Yafang Shao wrote: > 2017-09-26 19:26 GMT+08:00 Michal Hocko : > > On Tue 26-09-17 19:06:37, Yafang Shao wrote: [...] > >> Anyway, there's no document on that direct limits should not less than > >> background limits. > > > > Then improve the documentation. > > I have imp

Re: [PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-26 Thread Yafang Shao
2017-09-26 19:26 GMT+08:00 Michal Hocko : > On Tue 26-09-17 19:06:37, Yafang Shao wrote: >> 2017-09-26 18:25 GMT+08:00 Michal Hocko : >> > On Wed 20-09-17 06:43:35, Yafang Shao wrote: >> >> we can find the logic in domain_dirty_limits() that >> >> when dirty bg_thresh is bigger than dirty thresh, >

Re: [PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-26 Thread Michal Hocko
On Tue 26-09-17 19:06:37, Yafang Shao wrote: > 2017-09-26 18:25 GMT+08:00 Michal Hocko : > > On Wed 20-09-17 06:43:35, Yafang Shao wrote: > >> we can find the logic in domain_dirty_limits() that > >> when dirty bg_thresh is bigger than dirty thresh, > >> bg_thresh will be set as thresh * 1 / 2. > >

Re: [PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-26 Thread Yafang Shao
2017-09-26 18:25 GMT+08:00 Michal Hocko : > On Wed 20-09-17 06:43:35, Yafang Shao wrote: >> we can find the logic in domain_dirty_limits() that >> when dirty bg_thresh is bigger than dirty thresh, >> bg_thresh will be set as thresh * 1 / 2. >> if (bg_thresh >= thresh) >> bg_thre

Re: [PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-26 Thread Michal Hocko
On Wed 20-09-17 06:43:35, Yafang Shao wrote: > we can find the logic in domain_dirty_limits() that > when dirty bg_thresh is bigger than dirty thresh, > bg_thresh will be set as thresh * 1 / 2. > if (bg_thresh >= thresh) > bg_thresh = thresh / 2; > > But actually we can set vm

[PATCH v3] mm: introduce validity check on vm dirtiness settings

2017-09-19 Thread Yafang Shao
we can find the logic in domain_dirty_limits() that when dirty bg_thresh is bigger than dirty thresh, bg_thresh will be set as thresh * 1 / 2. if (bg_thresh >= thresh) bg_thresh = thresh / 2; But actually we can set vm background dirtiness bigger than vm dirtiness successfu