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


Groups > linux.kernel > #1229839

Re: ARM64 readahead: fault retry breaks mmap file read random detection

From Will Deacon <will.deacon@arm.com>
Newsgroups linux.kernel
Subject Re: ARM64 readahead: fault retry breaks mmap file read random detection
Date 2015-09-22 02:00 +0200
Message-ID <qbja1-57d-5@gated-at.bofh.it> (permalink)
References <qbgca-NQ-19@gated-at.bofh.it> <qbgvw-1pI-13@gated-at.bofh.it> <qbgYy-1Xv-9@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Mon, Sep 21, 2015 at 10:36:40PM +0100, Mark Salyzyn wrote:
> On 09/21/2015 02:09 PM, Will Deacon wrote:
> > On Mon, Sep 21, 2015 at 09:39:50PM +0100, Mark Salyzyn wrote:
> >> Description from commit 45cac65b0fcd
> >>      ("readahead: fault retry breaks mmap file read random detection")
> >> . . .
> >> Yup, arm64 needs this too! Random read improves by 250%, sequential
> >> read improves by 40%, and random write by 400% to an eMMC device with
> >> dm crypto wrapped around it.
> > Thanks for this. This must've gone in whilst we were developing the initial
> > version of the arm64 port and has since gone unnoticed.
> >
> > I'll queue it on the arm64 fixes branch and send a pull request after
> > some testing.
> >
> As noted, this fix may need to be propagated to all the arch-specific 
> code, I was not in a position to check this out on arm (32 bit) and the 
> benchmarking code I used did not immediately port to 32-bit.

You lost me; which arch-specific code are you referring to? The original
patch (in mainline) touches a whole bunch of architectures.

Will
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

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


Thread

ARM64 readahead: fault retry breaks mmap file read random detection Mark Salyzyn <salyzyn@android.com> - 2015-09-21 22:50 +0200
  Re: ARM64 readahead: fault retry breaks mmap file read random  detection Will Deacon <will.deacon@arm.com> - 2015-09-21 23:10 +0200
    Re: ARM64 readahead: fault retry breaks mmap file read random  detection Mark Salyzyn <salyzyn@android.com> - 2015-09-21 23:40 +0200
      Re: ARM64 readahead: fault retry breaks mmap file read random  detection Will Deacon <will.deacon@arm.com> - 2015-09-22 02:00 +0200
        Re: ARM64 readahead: fault retry breaks mmap file read random  detection Mark Salyzyn <salyzyn@android.com> - 2015-09-22 16:20 +0200

csiph-web