On Wed, Dec 01, 2021 at 02:52:01PM +0100, Mike Galbraith wrote: > On Wed, 2021-12-01 at 13:01 +0000, Mel Gorman wrote: > > On Tue, Nov 30, 2021 at 06:59:58PM +0100, Mike Galbraith wrote: > > > On Tue, 2021-11-30 at 17:27 +0000, Mel Gorman wrote: > > > > > > > > Obviously a fairly different experience and most likely due to > > > > the > > > > underlying storage. > > > > > > I bet a virtual nickle this is the sore spot. > > > > > > > You win a virtual nickle! > > I'm rich I'm rich... oh dang, virtual. > > I went back to 5.15, and confirmed that wait_iff_congested() did not > ever sleep with the try to eat /dev/zero load. Nor did it with insane > overcommit swap storm from hell with as much IO going on as my little > box is capable of generating, making the surrounding congestion bits > look.. down right expendable. > wait_iff_congested was broken once the block layer stopped tracking congestion and became a glorified cond_resched() in most cases. This is why the series aimed to remove the reliance on congestion_wait/wait_iff_congested. -- Mel Gorman SUSE Labs