On Wed, Jan 30, 2019 at 12:21:07PM +0000, Chris Mason wrote: > > > On 29 Jan 2019, at 23:17, Dave Chinner wrote: > > > From: Dave Chinner <dchinner@xxxxxxxxxx> > > > > This reverts commit a76cf1a474d7dbcd9336b5f5afb0162baa142cf0. > > > > This change causes serious changes to page cache and inode cache > > behaviour and balance, resulting in major performance regressions > > when combining worklaods such as large file copies and kernel > > compiles. > > > > https://bugzilla.kernel.org/show_bug.cgi?id=202441 > > I'm a little confused by the latest comment in the bz: > > https://bugzilla.kernel.org/show_bug.cgi?id=202441#c24 Which says the first patch that changed the shrinker behaviour is the underlying cause of the regression. > Are these reverts sufficient? I think so. > Roman beat me to suggesting Rik's followup. We hit a different problem > in prod with small slabs, and have a lot of instrumentation on Rik's > code helping. I think that's just another nasty, expedient hack that doesn't solve the underlying problem. Solving the underlying problem does not require changing core reclaim algorithms and upsetting a page reclaim/shrinker balance that has been stable and worked well for just about everyone for years. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
