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261eeb9c15
We've added a new mount options, "checkpoint_merge" and "nocheckpoint_merge", which creates a kernel daemon and makes it to merge concurrent checkpoint requests as much as possible to eliminate redundant checkpoint issues. Plus, we can eliminate the sluggish issue caused by slow checkpoint operation when the checkpoint is done in a process context in a cgroup having low i/o budget and cpu shares. To make this do better, we set the default i/o priority of the kernel daemon to "3", to give one higher priority than other kernel threads. The below verification result explains this. The basic idea has come from https://opensource.samsung.com. [Verification] Android Pixel Device(ARM64, 7GB RAM, 256GB UFS) Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20) Set "strict_guarantees" to "1" in BFQ tunables In "fg" cgroup, - thread A => trigger 1000 checkpoint operations "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1; done" - thread B => gererating async. I/O "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1 --filename=test_img --name=test" In "bg" cgroup, - thread C => trigger repeated checkpoint operations "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file; fsync test_dir2; done" We've measured thread A's execution time. [ w/o patch ] Elapsed Time: Avg. 68 seconds [ w/ patch ] Elapsed Time: Avg. 48 seconds Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> [Jaegeuk Kim: fix the return value in f2fs_start_ckpt_thread, reported by Dan] Signed-off-by: Daeho Jeong <daehojeong@google.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> |
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| .. | ||
| acl.c | ||
| acl.h | ||
| checkpoint.c | ||
| compress.c | ||
| compress.h | ||
| data.c | ||
| debug.c | ||
| dir.c | ||
| extent_cache.c | ||
| f2fs.h | ||
| file.c | ||
| gc.c | ||
| gc.h | ||
| hash.c | ||
| inline.c | ||
| inode.c | ||
| Kconfig | ||
| Makefile | ||
| namei.c | ||
| node.c | ||
| node.h | ||
| recovery.c | ||
| segment.c | ||
| segment.h | ||
| shrinker.c | ||
| super.c | ||
| sysfs.c | ||
| verity.c | ||
| xattr.c | ||
| xattr.h | ||