Commit 52190933 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: sysfs: introduce critical_task_priority 



This patch introduces /sys/fs/f2fs/<disk>/critical_task_priority, w/
this new sysfs interface, we can tune priority of f2fs_ckpt thread and
f2fs_gc thread.

Signed-off-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent bc367775

Documentation/ABI/testing/sysfs-fs-f2fs

+8 −0
Original line number Diff line number Diff line
@@ -987,3 +987,11 @@ Contact: "Chao Yu" <chao@kernel.org> 
Description:	f2fs can tune priority of thread which has entered into critical region covered by

		f2fs rwsemphore lock. This sysfs entry can be used to control priority value, the

		range is [100,139], by default the value is 120.



What:		/sys/fs/f2fs/<disk>/critical_task_priority

Date:		February 2026

Contact:	"Chao Yu" <chao@kernel.org>

Description:	It can be used to tune priority of f2fs critical task, e.g. f2fs_ckpt, f2fs_gc

		threads, limitation as below:

		- it requires user has CAP_SYS_NICE capability.

		- the range is [100, 139], by default the value is 100.

fs/f2fs/checkpoint.c

+2 −0
Original line number Diff line number Diff line
@@ -2158,6 +2158,8 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi) 
	}



	set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);

	set_user_nice(cprc->f2fs_issue_ckpt,

			PRIO_TO_NICE(sbi->critical_task_priority));



	return 0;

}

fs/f2fs/f2fs.h

+4 −0
Original line number Diff line number Diff line
@@ -1593,6 +1593,7 @@ enum node_type { 
#define MAX_LOCK_ELAPSED_TIME		500



#define F2FS_DEFAULT_TASK_PRIORITY		(DEFAULT_PRIO)

#define F2FS_CRITICAL_TASK_PRIORITY		NICE_TO_PRIO(0)



static inline int f2fs_test_bit(unsigned int nr, char *addr);

static inline void f2fs_set_bit(unsigned int nr, char *addr);
@@ -2010,6 +2011,9 @@ struct f2fs_sb_info { 
	/* adjust priority for task which is in critical region covered by lock */

	unsigned int lock_duration_priority;



	/* priority for critical task, e.g. f2fs_ckpt, f2fs_gc threads */

	long critical_task_priority;



#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 */

fs/f2fs/gc.c

+2 −0
Original line number Diff line number Diff line
@@ -234,6 +234,8 @@ int f2fs_start_gc_thread(struct f2fs_sb_info *sbi) 
		return err;

	}



	set_user_nice(gc_th->f2fs_gc_task,

			PRIO_TO_NICE(sbi->critical_task_priority));

	return 0;

}

fs/f2fs/super.c

+1 −0
Original line number Diff line number Diff line
@@ -4340,6 +4340,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi) 
	sbi->max_lock_elapsed_time = MAX_LOCK_ELAPSED_TIME;

	sbi->adjust_lock_priority = 0;

	sbi->lock_duration_priority = F2FS_DEFAULT_TASK_PRIORITY;

	sbi->critical_task_priority = F2FS_CRITICAL_TASK_PRIORITY;



	sbi->sum_blocksize = f2fs_sb_has_packed_ssa(sbi) ?

		4096 : sbi->blocksize;