On Thu, May 22, 2025 at 01:23:56PM +0200, Arnd Bergmann wrote: > On Thu, May 22, 2025, at 08:39, Peng Fan wrote: > > Hi Kent, Arnd > > > > There is below build error with "make ARCH=arm randconfig; make" > > > > fs/bcachefs/data_update.c: In function > > '__bch2_data_update_index_update': > > fs/bcachefs/data_update.c:439:1: error: the frame size of 1552 bytes is > > larger than 1280 bytes [-Werror=frame-larger-than=] > > Right, I think that's been the case with bcachefs since the start, > and I see it with allmodconfig as well, the problem being mostly > CONFIG_KASAN_STACK. > > There are a couple of bcachefs functions that have an unusual number > of local struct variables in them, and KASAN_STACK adds a redzone > around each one of them, further increasing the size. > > When I add "depends on !KASAN_STACK" to bcachefs, I see all > randconfig builds succeeding, but that may not be the best > solution.
Post 6.16, all the bcachefs functions I know of with high stack usage run with nearly the full stack available - they're running from a workqueue, or they're fsck, so this should be a non issue - I recently did some testing with max stack tracing usage enabled and our stack usage looks ok now.
