From e4b75621fc439399b94c4265cb54d2bda1177397 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Sun, 4 Jan 2026 10:07:17 +0800 Subject: [PATCH] f2fs: sysfs: introduce max_lock_elapsed_time This patch add a new sysfs node in /sys/fs/f2fs//max_lock_elapsed_time. This is a threshold, once a thread enters critical region that lock covers, total elapsed time exceeds this threshold, f2fs will print tracepoint to dump information of related context. This sysfs entry can be used to control the value of threshold, by default, the value is 500 ms. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- Documentation/ABI/testing/sysfs-fs-f2fs | 8 ++++++++ fs/f2fs/checkpoint.c | 2 +- fs/f2fs/f2fs.h | 3 +++ fs/f2fs/super.c | 1 + fs/f2fs/sysfs.c | 2 ++ 5 files changed, 15 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index c39a85e84b6b3..648ddd0d59f6f 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -939,3 +939,11 @@ Description: Controls write priority in multi-devices setups. A value of 0 means allocate_section_policy = 1 Prioritize writing to section before allocate_section_hint allocate_section_policy = 2 Prioritize writing to section after allocate_section_hint =========================== ========================================================== + +What: /sys/fs/f2fs//max_lock_elapsed_time +Date: December 2025 +Contact: "Chao Yu" +Description: This is a threshold, once a thread enters critical region that lock covers, total + elapsed time exceeds this threshold, f2fs will print tracepoint to dump information + of related context. This sysfs entry can be used to control the value of threshold, + by default, the value is 500 ms. diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index bc6058a3122b1..61bcf227d8ca9 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -66,7 +66,7 @@ static inline void trace_lock_elapsed_time_end(struct f2fs_rwsem *sem, get_lock_elapsed_time(&tts); total_time = div_u64(tts.total_time - lc->ts.total_time, npm); - if (total_time <= MAX_LOCK_ELAPSED_TIME) + if (total_time <= sem->sbi->max_lock_elapsed_time) return; #ifdef CONFIG_64BIT diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index fc3f532972edc..7f2675ed7f860 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1951,6 +1951,9 @@ struct f2fs_sb_info { /* carve out reserved_blocks from total blocks */ bool carve_out; + /* max elapsed time threshold in critical region that lock covered */ + unsigned long long max_lock_elapsed_time; + #ifdef CONFIG_F2FS_FS_COMPRESSION struct kmem_cache *page_array_slab; /* page array entry */ unsigned int page_array_slab_size; /* default page array slab size */ diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 036ba9cc799c0..8fe1ac8a609cd 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4295,6 +4295,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi) sbi->max_fragment_hole = DEF_FRAGMENT_SIZE; spin_lock_init(&sbi->gc_remaining_trials_lock); atomic64_set(&sbi->current_atomic_write, 0); + sbi->max_lock_elapsed_time = MAX_LOCK_ELAPSED_TIME; sbi->dir_level = DEF_DIR_LEVEL; sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL; diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index c42f4f979d13f..e03cba5a9d703 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -1219,6 +1219,7 @@ F2FS_SBI_GENERAL_RW_ATTR(blkzone_alloc_policy); F2FS_SBI_GENERAL_RW_ATTR(carve_out); F2FS_SBI_GENERAL_RW_ATTR(reserved_pin_section); F2FS_SBI_GENERAL_RW_ATTR(bggc_io_aware); +F2FS_SBI_GENERAL_RW_ATTR(max_lock_elapsed_time); /* STAT_INFO ATTR */ #ifdef CONFIG_F2FS_STAT_FS @@ -1422,6 +1423,7 @@ static struct attribute *f2fs_attrs[] = { ATTR_LIST(reserved_pin_section), ATTR_LIST(allocate_section_hint), ATTR_LIST(allocate_section_policy), + ATTR_LIST(max_lock_elapsed_time), NULL, }; ATTRIBUTE_GROUPS(f2fs); -- 2.47.3