Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > Hi Huang, > > On Tue, May 02, 2017 at 01:35:24PM +0800, Huang, Ying wrote: >> Hi, Minchan, >> >> Minchan Kim writes: >> >> > On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: >> >> In fact, during the test, I found the

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > Hi Huang, > > On Tue, May 02, 2017 at 01:35:24PM +0800, Huang, Ying wrote: >> Hi, Minchan, >> >> Minchan Kim writes: >> >> > On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: >> >> In fact, during the test, I found the overhead of sort() is comparable >> >>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Hi Huang, On Tue, May 02, 2017 at 01:35:24PM +0800, Huang, Ying wrote: > Hi, Minchan, > > Minchan Kim writes: > > > On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: > >> In fact, during the test, I found the overhead of sort() is comparable > >> with the

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Hi Huang, On Tue, May 02, 2017 at 01:35:24PM +0800, Huang, Ying wrote: > Hi, Minchan, > > Minchan Kim writes: > > > On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: > >> In fact, during the test, I found the overhead of sort() is comparable > >> with the performance difference of

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Hi, Minchan, Minchan Kim writes: > On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: >> In fact, during the test, I found the overhead of sort() is comparable >> with the performance difference of adding likely()/unlikely() to the >> "if" in the function. > >

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Hi, Minchan, Minchan Kim writes: > On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: >> In fact, during the test, I found the overhead of sort() is comparable >> with the performance difference of adding likely()/unlikely() to the >> "if" in the function. > > Huang, > > This

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: > In fact, during the test, I found the overhead of sort() is comparable > with the performance difference of adding likely()/unlikely() to the > "if" in the function. Huang, This discussion is started from your optimization code:

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 28, 2017 at 09:35:37PM +0800, Huang, Ying wrote: > In fact, during the test, I found the overhead of sort() is comparable > with the performance difference of adding likely()/unlikely() to the > "if" in the function. Huang, This discussion is started from your optimization code:

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

"Huang, Ying" writes: > Minchan Kim writes: > >> On Fri, Apr 28, 2017 at 04:05:26PM +0800, Huang, Ying wrote: >>> Minchan Kim writes: >>> >>> > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: >>> >> Minchan Kim

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

"Huang, Ying" writes: > Minchan Kim writes: > >> On Fri, Apr 28, 2017 at 04:05:26PM +0800, Huang, Ying wrote: >>> Minchan Kim writes: >>> >>> > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: >>> >> Minchan Kim writes: >>> >> >>> >> > On Wed, Apr 26, 2017 at 08:42:10PM +0800,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 28, 2017 at 04:05:26PM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: >> >> Minchan Kim writes: >> >> >> >> > On Wed, Apr 26,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 28, 2017 at 04:05:26PM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: >> >> Minchan Kim writes: >> >> >> >> > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: >> >> >> Minchan

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 28, 2017 at 04:05:26PM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: > >> Minchan Kim writes: > >> > >> > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: > >>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 28, 2017 at 04:05:26PM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: > >> Minchan Kim writes: > >> > >> > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: > >> >> Minchan Kim writes: > >> >> > >> >>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: >> >> Minchan Kim writes: >> >> >> >> > On Fri, Apr 21,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: >> >> Minchan Kim writes: >> >> >> >> > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> >> >> "Huang,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: > >> Minchan Kim writes: > >> > >> > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: > >>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 28, 2017 at 09:09:53AM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: > >> Minchan Kim writes: > >> > >> > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: > >> >> "Huang, Ying" writes: > >> >> > >>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> >> "Huang, Ying" writes: >> >> >> >> > Minchan Kim

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> >> "Huang, Ying" writes: >> >> >> >> > Minchan Kim writes: >> >> > >> >> >> On Wed, Apr 19, 2017 at 04:14:43PM

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Thu, 2017-04-27 at 09:21 +0800, Huang, Ying wrote: > Tim Chen writes: > > > > > > > > > > > > From 7bd903c42749c448ef6acbbdee8dcbc1c5b498b9 Mon Sep 17 00:00:00 2001 > > > From: Huang Ying > > > Date: Thu, 23 Feb 2017 13:05:20 +0800 > > >

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Thu, 2017-04-27 at 09:21 +0800, Huang, Ying wrote: > Tim Chen writes: > > > > > > > > > > > > From 7bd903c42749c448ef6acbbdee8dcbc1c5b498b9 Mon Sep 17 00:00:00 2001 > > > From: Huang Ying > > > Date: Thu, 23 Feb 2017 13:05:20 +0800 > > > Subject: [PATCH -v5] mm, swap: Sort swap entries

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: > >> "Huang, Ying" writes: > >> > >> > Minchan Kim writes: > >> > > >> >> On Wed,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Wed, Apr 26, 2017 at 08:42:10PM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: > >> "Huang, Ying" writes: > >> > >> > Minchan Kim writes: > >> > > >> >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > >> >>>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Tim Chen writes: >> >> From 7bd903c42749c448ef6acbbdee8dcbc1c5b498b9 Mon Sep 17 00:00:00 2001 >> From: Huang Ying >> Date: Thu, 23 Feb 2017 13:05:20 +0800 >> Subject: [PATCH -v5] mm, swap: Sort swap entries before free >> >>  >> --- >>  

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Tim Chen writes: >> >> From 7bd903c42749c448ef6acbbdee8dcbc1c5b498b9 Mon Sep 17 00:00:00 2001 >> From: Huang Ying >> Date: Thu, 23 Feb 2017 13:05:20 +0800 >> Subject: [PATCH -v5] mm, swap: Sort swap entries before free >> >>  >> --- >>  mm/swapfile.c | 43

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

> > From 7bd903c42749c448ef6acbbdee8dcbc1c5b498b9 Mon Sep 17 00:00:00 2001 > From: Huang Ying > Date: Thu, 23 Feb 2017 13:05:20 +0800 > Subject: [PATCH -v5] mm, swap: Sort swap entries before free > >  > --- >  mm/swapfile.c | 43

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

> > From 7bd903c42749c448ef6acbbdee8dcbc1c5b498b9 Mon Sep 17 00:00:00 2001 > From: Huang Ying > Date: Thu, 23 Feb 2017 13:05:20 +0800 > Subject: [PATCH -v5] mm, swap: Sort swap entries before free > >  > --- >  mm/swapfile.c | 43 ++- >  1 file changed,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> "Huang, Ying" writes: >> >> > Minchan Kim writes: >> > >> >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> >>> Minchan Kim

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> "Huang, Ying" writes: >> >> > Minchan Kim writes: >> > >> >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> >>> Minchan Kim writes: >> >>> >> >>> > Hi Huang, >> >>> > >> >>> > On Fri, Apr

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Sun, 2017-04-23 at 21:16 +0800, Huang, Ying wrote: > Tim Chen writes: > > > > > On Fri, 2017-04-21 at 20:29 +0800, Huang, Ying wrote: > > > > > > "Huang, Ying" writes: > > > > > > > > > > > > > > > Minchan Kim

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Sun, 2017-04-23 at 21:16 +0800, Huang, Ying wrote: > Tim Chen writes: > > > > > On Fri, 2017-04-21 at 20:29 +0800, Huang, Ying wrote: > > > > > > "Huang, Ying" writes: > > > > > > > > > > > > > > > Minchan Kim writes: > > > > > > > > > > > > > > > > > > > On Wed, Apr 19, 2017 at

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> "Huang, Ying" writes: >> >> > Minchan Kim writes: >> > >> >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> >>> Minchan Kim

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: >> "Huang, Ying" writes: >> >> > Minchan Kim writes: >> > >> >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> >>> Minchan Kim writes: >> >>> >> >>> > Hi Huang, >> >>> > >> >>> > On Fri, Apr

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: > "Huang, Ying" writes: > > > Minchan Kim writes: > > > >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > >>> Minchan Kim writes: > >>> > >>> > Hi Huang,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, Apr 21, 2017 at 08:29:30PM +0800, Huang, Ying wrote: > "Huang, Ying" writes: > > > Minchan Kim writes: > > > >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > >>> Minchan Kim writes: > >>> > >>> > Hi Huang, > >>> > > >>> > On Fri, Apr 07, 2017 at 02:49:01PM +0800,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Tim Chen writes: > On Fri, 2017-04-21 at 20:29 +0800, Huang, Ying wrote: >> "Huang, Ying" writes: >> >> > >> > Minchan Kim writes: >> > >> > > >> > > On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> > > >

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Tim Chen writes: > On Fri, 2017-04-21 at 20:29 +0800, Huang, Ying wrote: >> "Huang, Ying" writes: >> >> > >> > Minchan Kim writes: >> > >> > > >> > > On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> > > > >> > > > Minchan Kim writes: >> > > > >> > > > > >> > > > > Hi

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, 2017-04-21 at 20:29 +0800, Huang, Ying wrote: > "Huang, Ying" writes: > > > > > Minchan Kim writes: > > > > > > > > On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > > > > > > > > Minchan Kim writes: > > > >

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, 2017-04-21 at 20:29 +0800, Huang, Ying wrote: > "Huang, Ying" writes: > > > > > Minchan Kim writes: > > > > > > > > On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > > > > > > > > Minchan Kim writes: > > > > > > > > > > > > > > Hi Huang, > > > > > > > > > > On Fri,

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

"Huang, Ying" writes: > Minchan Kim writes: > >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >>> Minchan Kim writes: >>> >>> > Hi Huang, >>> > >>> > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: >>>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

"Huang, Ying" writes: > Minchan Kim writes: > >> On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >>> Minchan Kim writes: >>> >>> > Hi Huang, >>> > >>> > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: >>> >> From: Huang Ying >>> >> >>> >> void

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > Hi Huang, >> > >> > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: >> >> From: Huang Ying >> >> >> >>

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: >> Minchan Kim writes: >> >> > Hi Huang, >> > >> > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: >> >> From: Huang Ying >> >> >> >> To reduce the lock contention of swap_info_struct->lock when

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > Hi Huang, > > > > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: > >> From: Huang Ying > >> > >> To reduce the lock contention of

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Wed, Apr 19, 2017 at 04:14:43PM +0800, Huang, Ying wrote: > Minchan Kim writes: > > > Hi Huang, > > > > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: > >> From: Huang Ying > >> > >> To reduce the lock contention of swap_info_struct->lock when freeing > >> swap entry. The

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > Hi Huang, > > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: >> From: Huang Ying >> >> To reduce the lock contention of swap_info_struct->lock when freeing >> swap entry. The freed swap entries will be collected in

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Minchan Kim writes: > Hi Huang, > > On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: >> From: Huang Ying >> >> To reduce the lock contention of swap_info_struct->lock when freeing >> swap entry. The freed swap entries will be collected in a per-CPU >> buffer firstly, and be really

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Hi Huang, On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: > From: Huang Ying > > To reduce the lock contention of swap_info_struct->lock when freeing > swap entry. The freed swap entries will be collected in a per-CPU > buffer firstly, and be really freed

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Hi Huang, On Fri, Apr 07, 2017 at 02:49:01PM +0800, Huang, Ying wrote: > From: Huang Ying > > To reduce the lock contention of swap_info_struct->lock when freeing > swap entry. The freed swap entries will be collected in a per-CPU > buffer firstly, and be really freed later in batch. During

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Andrew Morton writes: > On Fri, 7 Apr 2017 14:49:01 +0800 "Huang, Ying" wrote: > >> To reduce the lock contention of swap_info_struct->lock when freeing >> swap entry. The freed swap entries will be collected in a per-CPU >> buffer firstly, and

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Andrew Morton writes: > On Fri, 7 Apr 2017 14:49:01 +0800 "Huang, Ying" wrote: > >> To reduce the lock contention of swap_info_struct->lock when freeing >> swap entry. The freed swap entries will be collected in a per-CPU >> buffer firstly, and be really freed later in batch. During the

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Andrew Morton writes: > On Fri, 7 Apr 2017 14:49:01 +0800 "Huang, Ying" wrote: > >> To reduce the lock contention of swap_info_struct->lock when freeing >> swap entry. The freed swap entries will be collected in a per-CPU >> buffer firstly, and

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

Andrew Morton writes: > On Fri, 7 Apr 2017 14:49:01 +0800 "Huang, Ying" wrote: > >> To reduce the lock contention of swap_info_struct->lock when freeing >> swap entry. The freed swap entries will be collected in a per-CPU >> buffer firstly, and be really freed later in batch. During the

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, 7 Apr 2017 14:49:01 +0800 "Huang, Ying" wrote: > To reduce the lock contention of swap_info_struct->lock when freeing > swap entry. The freed swap entries will be collected in a per-CPU > buffer firstly, and be really freed later in batch. During the batch >

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, 7 Apr 2017 14:49:01 +0800 "Huang, Ying" wrote: > To reduce the lock contention of swap_info_struct->lock when freeing > swap entry. The freed swap entries will be collected in a per-CPU > buffer firstly, and be really freed later in batch. During the batch > freeing, if the

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, 2017-04-07 at 14:49 +0800, Huang, Ying wrote: > To solve the issue, the per-CPU buffer is sorted according to the > swap > device before freeing the swap entries.  Test shows that the time > spent by swapcache_free_entries() could be reduced after the patch. > > Test the patch via

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free

On Fri, 2017-04-07 at 14:49 +0800, Huang, Ying wrote: > To solve the issue, the per-CPU buffer is sorted according to the > swap > device before freeing the swap entries.  Test shows that the time > spent by swapcache_free_entries() could be reduced after the patch. > > Test the patch via

[PATCH -mm -v3] mm, swap: Sort swap entries before free

From: Huang Ying To reduce the lock contention of swap_info_struct->lock when freeing swap entry. The freed swap entries will be collected in a per-CPU buffer firstly, and be really freed later in batch. During the batch freeing, if the consecutive swap entries in the

[PATCH -mm -v3] mm, swap: Sort swap entries before free

From: Huang Ying To reduce the lock contention of swap_info_struct->lock when freeing swap entry. The freed swap entries will be collected in a per-CPU buffer firstly, and be really freed later in batch. During the batch freeing, if the consecutive swap entries in the per-CPU buffer belongs to