From: Minchan Kim <minchan@kernel.org>
To: "Huang, Ying" <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Hugh Dickins <hughd@google.com>, Shaohua Li <shli@kernel.org>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free
Date: Tue, 2 May 2017 14:02:28 +0900 [thread overview]
Message-ID: <20170502050228.GA27176@bbox> (raw)
In-Reply-To: <878tmkvemu.fsf@yhuang-dev.intel.com>
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:
if (nr_swapfiles > 1)
sort();
I don't have such fast machine so cannot test it. However, you added
such optimization code in there so I guess it's *worth* to review so
with spending my time, I pointed out what you are missing and
suggested a idea to find a compromise.
Now you are saying sort is so fast so no worth to add more logics
to avoid the overhead?
Then, please just drop that if condition part and instead, sort
it unconditionally.
WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan@kernel.org>
To: "Huang, Ying" <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Hugh Dickins <hughd@google.com>, Shaohua Li <shli@kernel.org>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free
Date: Tue, 2 May 2017 14:02:28 +0900 [thread overview]
Message-ID: <20170502050228.GA27176@bbox> (raw)
In-Reply-To: <878tmkvemu.fsf@yhuang-dev.intel.com>
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:
if (nr_swapfiles > 1)
sort();
I don't have such fast machine so cannot test it. However, you added
such optimization code in there so I guess it's *worth* to review so
with spending my time, I pointed out what you are missing and
suggested a idea to find a compromise.
Now you are saying sort is so fast so no worth to add more logics
to avoid the overhead?
Then, please just drop that if condition part and instead, sort
it unconditionally.
--
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next prev parent reply other threads:[~2017-05-02 5:02 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-07 6:49 [PATCH -mm -v3] mm, swap: Sort swap entries before free Huang, Ying
2017-04-07 6:49 ` Huang, Ying
2017-04-07 13:05 ` Rik van Riel
2017-04-07 13:05 ` Rik van Riel
2017-04-07 21:43 ` Andrew Morton
2017-04-07 21:43 ` Andrew Morton
2017-04-11 7:03 ` Huang, Ying
2017-04-11 7:03 ` Huang, Ying
2017-04-14 1:36 ` Huang, Ying
2017-04-14 1:36 ` Huang, Ying
2017-04-14 1:41 ` Huang, Ying
2017-04-18 4:59 ` Minchan Kim
2017-04-18 4:59 ` Minchan Kim
2017-04-19 8:14 ` Huang, Ying
2017-04-19 8:14 ` Huang, Ying
2017-04-20 6:38 ` Minchan Kim
2017-04-20 6:38 ` Minchan Kim
2017-04-20 7:15 ` Huang, Ying
2017-04-20 7:15 ` Huang, Ying
2017-04-21 12:29 ` Huang, Ying
2017-04-21 12:29 ` Huang, Ying
2017-04-21 23:29 ` Tim Chen
2017-04-21 23:29 ` Tim Chen
2017-04-23 13:16 ` Huang, Ying
2017-04-23 13:16 ` Huang, Ying
2017-04-24 16:03 ` Tim Chen
2017-04-24 16:03 ` Tim Chen
2017-04-24 4:52 ` Minchan Kim
2017-04-24 4:52 ` Minchan Kim
2017-04-24 6:47 ` Huang, Ying
2017-04-24 6:47 ` Huang, Ying
2017-04-26 12:42 ` Huang, Ying
2017-04-26 12:42 ` Huang, Ying
2017-04-26 20:13 ` Tim Chen
2017-04-26 20:13 ` Tim Chen
2017-04-27 1:21 ` Huang, Ying
2017-04-27 1:21 ` Huang, Ying
2017-04-27 16:48 ` Tim Chen
2017-04-27 16:48 ` Tim Chen
2017-04-27 4:35 ` Minchan Kim
2017-04-27 4:35 ` Minchan Kim
2017-04-28 1:09 ` Huang, Ying
2017-04-28 1:09 ` Huang, Ying
2017-04-28 7:42 ` Minchan Kim
2017-04-28 7:42 ` Minchan Kim
2017-04-28 8:05 ` Huang, Ying
2017-04-28 8:05 ` Huang, Ying
2017-04-28 9:00 ` Minchan Kim
2017-04-28 9:00 ` Minchan Kim
2017-04-28 11:48 ` Huang, Ying
2017-04-28 11:48 ` Huang, Ying
2017-04-28 13:35 ` Huang, Ying
2017-04-28 13:35 ` Huang, Ying
2017-05-02 5:02 ` Minchan Kim [this message]
2017-05-02 5:02 ` Minchan Kim
2017-05-02 5:35 ` Huang, Ying
2017-05-02 5:35 ` Huang, Ying
2017-05-02 5:48 ` Minchan Kim
2017-05-02 5:48 ` Minchan Kim
2017-05-02 6:08 ` Huang, Ying
2017-05-02 6:08 ` Huang, Ying
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