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authorConstantine Shulyupin <const@MakeLinux.com>2018-09-06 15:37:06 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2018-10-01 10:07:06 +0200
commit5da784cce4308ae10a79e3c8c41b13fb9568e4e0 (patch)
treef55416dec7532814d30c1dbd415ef11baec9fc7a /fs/fuse/dev.c
parent8a7aa286ab67d7dfac8abbefab899597b5977c9a (diff)
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fuse: add max_pages to init_out
Replace FUSE_MAX_PAGES_PER_REQ with the configurable parameter max_pages to improve performance. Old RFC with detailed description of the problem and many fixes by Mitsuo Hayasaka (mitsuo.hayasaka.hu@hitachi.com): - https://lkml.org/lkml/2012/7/5/136 We've encountered performance degradation and fixed it on a big and complex virtual environment. Environment to reproduce degradation and improvement: 1. Add lag to user mode FUSE Add nanosleep(&(struct timespec){ 0, 1000 }, NULL); to xmp_write_buf in passthrough_fh.c 2. patch UM fuse with configurable max_pages parameter. The patch will be provided latter. 3. run test script and perform test on tmpfs fuse_test() { cd /tmp mkdir -p fusemnt passthrough_fh -o max_pages=$1 /tmp/fusemnt grep fuse /proc/self/mounts dd conv=fdatasync oflag=dsync if=/dev/zero of=fusemnt/tmp/tmp \ count=1K bs=1M 2>&1 | grep -v records rm fusemnt/tmp/tmp killall passthrough_fh } Test results: passthrough_fh /tmp/fusemnt fuse.passthrough_fh \ rw,nosuid,nodev,relatime,user_id=0,group_id=0 0 0 1073741824 bytes (1.1 GB) copied, 1.73867 s, 618 MB/s passthrough_fh /tmp/fusemnt fuse.passthrough_fh \ rw,nosuid,nodev,relatime,user_id=0,group_id=0,max_pages=256 0 0 1073741824 bytes (1.1 GB) copied, 1.15643 s, 928 MB/s Obviously with bigger lag the difference between 'before' and 'after' will be more significant. Mitsuo Hayasaka, in 2012 (https://lkml.org/lkml/2012/7/5/136), observed improvement from 400-550 to 520-740. Signed-off-by: Constantine Shulyupin <const@MakeLinux.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse/dev.c')
-rw-r--r--fs/fuse/dev.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index fefb9dd8a2f4..69d4df78a417 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -61,6 +61,7 @@ static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
struct page **pages = NULL;
struct fuse_page_desc *page_descs = NULL;
+ WARN_ON(npages > FUSE_MAX_MAX_PAGES);
if (npages > FUSE_REQ_INLINE_PAGES) {
pages = kzalloc(npages * (sizeof(*pages) +
sizeof(*page_descs)), flags);
@@ -1674,7 +1675,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
unsigned int num;
unsigned int offset;
size_t total_len = 0;
- int num_pages;
+ unsigned int num_pages;
offset = outarg->offset & ~PAGE_MASK;
file_size = i_size_read(inode);
@@ -1686,7 +1687,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
num = file_size - outarg->offset;
num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
- num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
+ num_pages = min(num_pages, fc->max_pages);
req = fuse_get_req(fc, num_pages);
if (IS_ERR(req))