On Tue, 25 Jun 2024 19:06:42 +1000 Gavin Shan <gshan@xxxxxxxxxx> wrote: > Currently, xarray can't support arbitrary page cache size. More details > can be found from the WARN_ON() statement in xas_split_alloc(). In our > test whose code is attached below, we hit the WARN_ON() on ARM64 system > where the base page size is 64KB and huge page size is 512MB. The issue > was reported long time ago and some discussions on it can be found here > [1]. > > [1] https://www.spinics.net/lists/linux-xfs/msg75404.html > > In order to fix the issue, we need to adjust MAX_PAGECACHE_ORDER to one > supported by xarray and avoid PMD-sized page cache if needed. The code > changes are suggested by David Hildenbrand. > > PATCH[1] adjusts MAX_PAGECACHE_ORDER to that supported by xarray > PATCH[2-3] avoids PMD-sized page cache in the synchronous readahead path > PATCH[4] avoids PMD-sized page cache for shmem files if needed Questions on the timing of these. 1&2 are cc:stable whereas 3&4 are not. I could split them and feed 1&2 into 6.10-rcX and 3&4 into 6.11-rc1. A problem with this approach is that we're putting a basically untested combination into -stable: 1&2 might have bugs which were accidentally fixed in 3&4. A way to avoid this is to add cc:stable to all four patches. What are your thoughts on this matter?
