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Commit 2e3ee613 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'writeback-proportions' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux 

Pull writeback updates from Wu Fengguang:
 "Use time based periods to age the writeback proportions, which can
  adapt equally well to fast/slow devices."

Fix up trivial conflict in comment in fs/sync.c

* tag 'writeback-proportions' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Fix some comment errors
  block: Convert BDI proportion calculations to flexible proportions
  lib: Fix possible deadlock in flexible proportion code
  lib: Proportions with flexible period
parents 1fad1e9a 331cbdee

fs/fs-writeback.c

+2 −2
Original line number Diff line number Diff line
@@ -628,8 +628,8 @@ static long writeback_sb_inodes(struct super_block *sb, 
		}



		/*

		 * Don't bother with new inodes or inodes beeing freed, first

		 * kind does not need peridic writeout yet, and for the latter

		 * Don't bother with new inodes or inodes being freed, first

		 * kind does not need periodic writeout yet, and for the latter

		 * kind writeout is handled by the freer.

		 */

		spin_lock(&inode->i_lock);

fs/super.c

+1 −1
Original line number Diff line number Diff line
@@ -320,7 +320,7 @@ static int grab_super(struct super_block *s) __releases(sb_lock) 


/*

 *	grab_super_passive - acquire a passive reference

 *	@s: reference we are trying to grab

 *	@sb: reference we are trying to grab

 *

 *	Tries to acquire a passive reference. This is used in places where we

 *	cannot take an active reference but we need to ensure that the

include/linux/backing-dev.h

+2 −2
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ 


#include <linux/percpu_counter.h>

#include <linux/log2.h>

#include <linux/proportions.h>

#include <linux/flex_proportions.h>

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/sched.h>
@@ -89,7 +89,7 @@ struct backing_dev_info { 
	unsigned long dirty_ratelimit;

	unsigned long balanced_dirty_ratelimit;



	struct prop_local_percpu completions;

	struct fprop_local_percpu completions;

	int dirty_exceeded;



	unsigned int min_ratio;

include/linux/flex_proportions.h

0 → 100644
+101 −0
Original line number Diff line number Diff line 
/*

 * Floating proportions with flexible aging period

 *

 *  Copyright (C) 2011, SUSE, Jan Kara <jack@suse.cz>

 */



#ifndef _LINUX_FLEX_PROPORTIONS_H

#define _LINUX_FLEX_PROPORTIONS_H



#include <linux/percpu_counter.h>

#include <linux/spinlock.h>

#include <linux/seqlock.h>



/*

 * When maximum proportion of some event type is specified, this is the

 * precision with which we allow limitting. Note that this creates an upper

 * bound on the number of events per period like

 *   ULLONG_MAX >> FPROP_FRAC_SHIFT.

 */

#define FPROP_FRAC_SHIFT 10

#define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT)



/*

 * ---- Global proportion definitions ----

 */

struct fprop_global {

	/* Number of events in the current period */

	struct percpu_counter events;

	/* Current period */

	unsigned int period;

	/* Synchronization with period transitions */

	seqcount_t sequence;

};



int fprop_global_init(struct fprop_global *p);

void fprop_global_destroy(struct fprop_global *p);

bool fprop_new_period(struct fprop_global *p, int periods);



/*

 *  ---- SINGLE ----

 */

struct fprop_local_single {

	/* the local events counter */

	unsigned long events;

	/* Period in which we last updated events */

	unsigned int period;

	raw_spinlock_t lock;	/* Protect period and numerator */

};



#define INIT_FPROP_LOCAL_SINGLE(name)			\

{	.lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock),	\

}



int fprop_local_init_single(struct fprop_local_single *pl);

void fprop_local_destroy_single(struct fprop_local_single *pl);

void __fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl);

void fprop_fraction_single(struct fprop_global *p,

	struct fprop_local_single *pl, unsigned long *numerator,

	unsigned long *denominator);



static inline

void fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl)

{

	unsigned long flags;



	local_irq_save(flags);

	__fprop_inc_single(p, pl);

	local_irq_restore(flags);

}



/*

 * ---- PERCPU ----

 */

struct fprop_local_percpu {

	/* the local events counter */

	struct percpu_counter events;

	/* Period in which we last updated events */

	unsigned int period;

	raw_spinlock_t lock;	/* Protect period and numerator */

};



int fprop_local_init_percpu(struct fprop_local_percpu *pl);

void fprop_local_destroy_percpu(struct fprop_local_percpu *pl);

void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl);

void __fprop_inc_percpu_max(struct fprop_global *p, struct fprop_local_percpu *pl,

			    int max_frac);

void fprop_fraction_percpu(struct fprop_global *p,

	struct fprop_local_percpu *pl, unsigned long *numerator,

	unsigned long *denominator);



static inline

void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)

{

	unsigned long flags;



	local_irq_save(flags);

	__fprop_inc_percpu(p, pl);

	local_irq_restore(flags);

}



#endif

lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ 
	 rbtree.o radix-tree.o dump_stack.o timerqueue.o\

	 idr.o int_sqrt.o extable.o prio_tree.o \

	 sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \

	 proportions.o prio_heap.o ratelimit.o show_mem.o \

	 proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \

	 is_single_threaded.o plist.o decompress.o



lib-$(CONFIG_MMU) += ioremap.o