On 05/26, Matthew Wilcox wrote: > On Tue, May 26, 2026 at 01:21:33AM +0000, Jaegeuk Kim wrote: > > On 05/24, Christoph Hellwig wrote: > > > On Fri, May 22, 2026 at 02:04:59PM +0000, Jaegeuk Kim wrote: > > > > This was a quick buddyinfo right after booting the device. > > > > > > > > Before: > > > > Node 0, zone Normal 22684 42284 28704 16901 9515 4566 1854 > > > > 673 181 36 758 > > > > > > > > After disabling EROFS large folio: > > > > Node 0, zone Normal 8486 4732 2175 1161 697 272 82 > > > > 19 3 1 856 > > > > > > And what are you trying to say us with that? > > > > This means, high-order pages were used up by EROFS which sets large folio by > > default. So, I wanted to say the concern was based on actual data which was > > what > > Mattew asked. > > This isn't that though. What you actually need is to show that high order > allocations are _failing_. The MM is far more complicated than you seem > to understand. There isn't a fixed number of large folios available; > when we try to allocate memory, we do reclaim. And if there's large > folios on the LRU list, you'll get them. > > If what you want is large folios readily available, then what you want > is large folios used _everywhere_ because then they're easy to get! > If there's small folios in use, you need to reclaim a lot of memory in > order to reassemble large folios (it's the birthday paradox, similar to > the hash collision problem).
Thanks for the feedback. Actually, I tried to do compact_memory before doing read() for AI loading, but I got complaints where it took hundreds milliseconds to run that compact_memory. Is there a good way to secure high-order pages before that read()? It was quite hard to project when it will happen. > > > _______________________________________________ > Linux-f2fs-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
