On 07/04/23 09:41, Yin, Fengwei wrote: > On 7/4/2023 2:49 AM, Mike Kravetz wrote: > > On 06/28/23 12:43, Yin Fengwei wrote: > > > > Thank you for your detailed analysis! > > > > When the regression was initially discovered, I sent a patch to revert > > commit 9425c591e06a. Andrew has picked up this change. And, Andrew has > > also picked up this patch. > Oh. I didn't notice that you sent revert patch. My understanding is that > commit 9425c591e06a is a good change. > > > > > I have not verified yet, but I suspect that this patch is going to cause > > a regression because it depends on the behavior of page_cache_next_miss > > in 9425c591e06a which has been reverted. > Yes. If the 9425c591e06a was reverted, this patch could introduce regression. > Which fixing do you prefer? reverting 9425c591e06a or this patch? Then we > can suggest to Andrew to take it. For now, I suggest we go with the revert. Why? - The revert is already going into stable trees. - I may not be remembering correctly, but I seem to recall Matthew mentioning plans to redo/redesign the page cache and possibly readahead code. If this is the case, then better to keep the legacy behavior for now. But, I am not sure if this is actually part of any plan or work in progress. -- Mike Kravetz
