Re: [PATCH v2] mm: introduce validity check on vm dirtiness settings

2017-09-20 Thread Yafang Shao
2017-09-20 23:33 GMT+08:00 Jan Kara : > On Tue 19-09-17 19:48:00, Yafang Shao wrote: >> 2017-09-19 16:35 GMT+08:00 Jan Kara : >> > On Tue 19-09-17 06:53:00, Yafang Shao wrote: >> >> + if (vm_dirty_bytes == 0 && vm_dirty_ratio == 0 && >> >> + (dirty_background_bytes != 0 || dirty_bac

Re: [PATCH v2] mm: introduce validity check on vm dirtiness settings

2017-09-20 Thread Jan Kara
On Tue 19-09-17 19:48:00, Yafang Shao wrote: > 2017-09-19 16:35 GMT+08:00 Jan Kara : > > On Tue 19-09-17 06:53:00, Yafang Shao wrote: > >> + if (vm_dirty_bytes == 0 && vm_dirty_ratio == 0 && > >> + (dirty_background_bytes != 0 || dirty_background_ratio != 0)) > >> + ret

Re: [PATCH v2] mm: introduce validity check on vm dirtiness settings

2017-09-19 Thread Yafang Shao
2017-09-19 16:35 GMT+08:00 Jan Kara : > On Tue 19-09-17 06:53:00, 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 =

Re: [PATCH v2] mm: introduce validity check on vm dirtiness settings

2017-09-19 Thread Jan Kara
On Tue 19-09-17 06:53:00, 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 v2] mm: introduce validity check on vm dirtiness settings

2017-09-18 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