| From 084d106b5fbb496fb030edcd53e2ebd7c5658d79 Mon Sep 17 00:00:00 2001 |
| From: Miklos Szeredi <mszeredi@redhat.com> |
| Date: Thu, 12 Sep 2019 14:28:13 +0200 |
| Subject: [PATCH] fuse: fix request limit |
| |
| commit f22f812d5ce75a18b56073a7a63862e6ea764070 upstream. |
| |
| 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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c |
| index 987877860c01..f3104db3de83 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; |
| -- |
| 2.7.4 |
| |
