Messages in this thread | | | Date | Thu, 8 Mar 2012 18:06:50 -0800 (PST) | From | Hugh Dickins <> | Subject | Re: [PATCH 3/7 v2] mm: rework __isolate_lru_page() file/anon filter |
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On Thu, 8 Mar 2012, KAMEZAWA Hiroyuki wrote: > On Tue, 6 Mar 2012 19:22:21 -0800 (PST) > Hugh Dickins <hughd@google.com> wrote: > > > > What does the compiler say (4.5.1 here, OPTIMIZE_FOR_SIZE off)? > > text data bss dec hex filename > > 17723 113 17 17853 45bd vmscan.o.0 > > 17671 113 17 17801 4589 vmscan.o.1 > > 17803 113 17 17933 460d vmscan.o.2 > > > > That suggests that your v2 is the worst and your v1 the best. > > Kame, can I persuade you to let the compiler decide on this? > > > > Hmm. How about Costa' proposal ? as > > int tmp_var = PageActive(page) ? ISOLATE_ACTIVE : ISOLATE_INACTIVE > if (!(mode & tmp_var)) > ret;
Yes, that would have been a good compromise (given a better name than "tmp_var"!), I didn't realize that one was acceptable to you.
But I see that Konstantin has been inspired by our disagreement to a more creative solution.
I like very much the look of what he's come up with, but I'm still puzzling over why it barely makes any improvement to __isolate_lru_page(): seems significantly inferior (in code size terms) to his original (which I imagine Glauber's compromise would be equivalent to).
At some point I ought to give up on niggling about this, but I haven't quite got there yet.
Hugh
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