Commit c7981433 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

writeback: make __wb_writeout_inc() and hard_dirty_limit() take wb_domaas a parameter 



Currently __wb_writeout_inc() and hard_dirty_limit() assume
global_wb_domain; however, cgroup writeback support requires
considering per-memcg wb_domain too.

This patch separates out domain-specific part of __wb_writeout_inc()
into wb_domain_writeout_inc() which takes wb_domain as a parameter and
adds the parameter to hard_dirty_limit().  This will allow these two
functions to handle per-memcg wb_domains.

This patch doesn't introduce any behavioral changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent e9f07dfd

mm/page-writeback.c

+21 −16
Original line number Diff line number Diff line
@@ -445,17 +445,12 @@ static unsigned long wp_next_time(unsigned long cur_time) 
	return cur_time;

}



/*

 * Increment the wb's writeout completion count and the global writeout

 * completion count. Called from test_clear_page_writeback().

 */

static inline void __wb_writeout_inc(struct bdi_writeback *wb)

static void wb_domain_writeout_inc(struct wb_domain *dom,

				   struct fprop_local_percpu *completions,

				   unsigned int max_prop_frac)

{

	struct wb_domain *dom = &global_wb_domain;



	__inc_wb_stat(wb, WB_WRITTEN);

	__fprop_inc_percpu_max(&dom->completions, &wb->completions,

			       wb->bdi->max_prop_frac);

	__fprop_inc_percpu_max(&dom->completions, completions,

			       max_prop_frac);

	/* First event after period switching was turned off? */

	if (!unlikely(dom->period_time)) {

		/*
@@ -469,6 +464,17 @@ static inline void __wb_writeout_inc(struct bdi_writeback *wb) 
	}

}



/*

 * Increment @wb's writeout completion count and the global writeout

 * completion count. Called from test_clear_page_writeback().

 */

static inline void __wb_writeout_inc(struct bdi_writeback *wb)

{

	__inc_wb_stat(wb, WB_WRITTEN);

	wb_domain_writeout_inc(&global_wb_domain, &wb->completions,

			       wb->bdi->max_prop_frac);

}



void wb_writeout_inc(struct bdi_writeback *wb)

{

	unsigned long flags;
@@ -571,10 +577,9 @@ static unsigned long dirty_freerun_ceiling(unsigned long thresh, 
	return (thresh + bg_thresh) / 2;

}



static unsigned long hard_dirty_limit(unsigned long thresh)

static unsigned long hard_dirty_limit(struct wb_domain *dom,

				      unsigned long thresh)

{

	struct wb_domain *dom = &global_wb_domain;



	return max(thresh, dom->dirty_limit);

}
@@ -744,7 +749,7 @@ static void wb_position_ratio(struct dirty_throttle_control *dtc) 
	struct bdi_writeback *wb = dtc->wb;

	unsigned long write_bw = wb->avg_write_bandwidth;

	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);

	unsigned long limit = hard_dirty_limit(dtc->thresh);

	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);

	unsigned long wb_thresh = dtc->wb_thresh;

	unsigned long x_intercept;

	unsigned long setpoint;		/* dirty pages' target balance point */
@@ -1029,7 +1034,7 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc, 
	struct bdi_writeback *wb = dtc->wb;

	unsigned long dirty = dtc->dirty;

	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);

	unsigned long limit = hard_dirty_limit(dtc->thresh);

	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);

	unsigned long setpoint = (freerun + limit) / 2;

	unsigned long write_bw = wb->avg_write_bandwidth;

	unsigned long dirty_ratelimit = wb->dirty_ratelimit;
@@ -1681,7 +1686,7 @@ void throttle_vm_writeout(gfp_t gfp_mask) 


        for ( ; ; ) {

		global_dirty_limits(&background_thresh, &dirty_thresh);

		dirty_thresh = hard_dirty_limit(dirty_thresh);

		dirty_thresh = hard_dirty_limit(&global_wb_domain, dirty_thresh);



                /*

                 * Boost the allowable dirty threshold a bit for page

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