On Tue, Feb 20, 2024 at 5:00 PM 李培锋 <lipeifeng@xxxxxxxx> wrote: > > > 在 2024/2/20 11:01, Barry Song 写道: > > Hi peifeng, > > > > On Tue, Feb 20, 2024 at 2:43 PM 李培锋 <lipeifeng@xxxxxxxx> wrote: > >> add more experts from Linux and Google. > >> > >> > >> 在 2024/2/19 22:17, lipeifeng@xxxxxxxx 写道: > >>> From: lipeifeng <lipeifeng@xxxxxxxx> > >>> > >>> The patch to support folio_referenced to control the bevavior > >>> of walk_rmap, which for some thread to hold the lock in rmap_walk > >>> instead of try_lock when using folio_referenced. > > please describe what problem the patch is trying to address, > > and why this modification is needed in commit message. > > Hi Barry： > > 1. the patch is one of the kshrinkd series patches. this seems like a bad name for the patchset as nobody knows what is kshrinkd. maybe something like "asynchronously reclaim contended folios rather than aging them"? > > 2. it is to support folio_referenced to control the bevavior of walk_rmap, > > kshrinkd would call folio_referenced through shrink_folio_list but it > doesn't > > want to try_lock in rmap_walk during folio_referenced. > > > > btw, who is set rw_try_lock to 0, what is the benefit? > > Actually, the current situation is that only shrink_folio_list will set > try_lock to 1， understood, as you don't want contended folios to be skipped by scanner any more. > > while others will be set to 0 that it would wait for rwsem-lock if > contened in rmap_walk. ok. other reclamation threads will still skip contended folios. As discussed, the patchset really needs detailed data to back up. Thanks Barry
