Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1634136

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

From Minchan Kim <minchan@kernel.org>
Newsgroups linux.kernel
Subject Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free
Date 2017-05-02 07:10 +0200
Message-ID <tCyet-1Ys-5@gated-at.bofh.it> (permalink)
References (5 earlier) <tB8P7-4n0-1@gated-at.bofh.it> <tB98u-4Ii-17@gated-at.bofh.it> <tBaed-5ps-1@gated-at.bofh.it> <tBczn-6JZ-17@gated-at.bofh.it> <tBehR-7VW-41@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


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.

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-04-26 14:50 +0200
  Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Tim Chen <tim.c.chen@linux.intel.com> - 2017-04-26 22:20 +0200
    Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-04-27 03:30 +0200
      Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Tim Chen <tim.c.chen@linux.intel.com> - 2017-04-27 18:50 +0200
  Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Minchan Kim <minchan@kernel.org> - 2017-04-27 06:50 +0200
    Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-04-28 03:20 +0200
      Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Minchan Kim <minchan@kernel.org> - 2017-04-28 09:50 +0200
        Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-04-28 10:10 +0200
          Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Minchan Kim <minchan@kernel.org> - 2017-04-28 11:20 +0200
            Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-04-28 13:50 +0200
              Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-04-28 15:40 +0200
                Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Minchan Kim <minchan@kernel.org> - 2017-05-02 07:10 +0200
                Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-05-02 07:40 +0200
                Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free Minchan Kim <minchan@kernel.org> - 2017-05-02 07:50 +0200
                Re: [PATCH -mm -v3] mm, swap: Sort swap entries before free "Huang\, Ying" <ying.huang@intel.com> - 2017-05-02 08:10 +0200

csiph-web