From: Miklos Szeredi mszeredi@redhat.com
[ Upstream commit f22f812d5ce75a18b56073a7a63862e6ea764070 ]
The size of struct fuse_req was reduced from 392B to 144B on a non-debug config, thus the sanitize_global_limit() helper was setting a larger default limit. This doesn't really reflect reduction in the memory used by requests, since the fields removed from fuse_req were added to fuse_args derived structs; e.g. sizeof(struct fuse_writepages_args) is 248B, thus resulting in slightly more memory being used for writepage requests overalll (due to using 256B slabs).
Make the calculatation ignore the size of fuse_req and use the old 392B value.
Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/fuse/inode.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 987877860c019..f3104db3de83a 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -823,9 +823,12 @@ static const struct super_operations fuse_super_operations = {
static void sanitize_global_limit(unsigned *limit) { + /* + * The default maximum number of async requests is calculated to consume + * 1/2^13 of the total memory, assuming 392 bytes per request. + */ if (*limit == 0) - *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / - sizeof(struct fuse_req); + *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;
if (*limit >= 1 << 16) *limit = (1 << 16) - 1;