lkml.org 
[lkml]   [2012]   [Oct]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH] add some drop_caches documentation and info messsge
    Date
    On Wednesday, October 24, 2012 06:17:52 PM Andrew Morton wrote:
    > On Thu, 25 Oct 2012 00:04:46 +0200 "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
    >
    > > On Wednesday 24 of October 2012 14:13:03 Andrew Morton wrote:
    > > > On Wed, 24 Oct 2012 23:06:00 +0200
    > > > Borislav Petkov <bp@alien8.de> wrote:
    > > >
    > > > > On Wed, Oct 24, 2012 at 01:48:36PM -0700, Andrew Morton wrote:
    > > > > > Well who knows. Could be that people's vm *does* suck. Or they have
    > > > > > some particularly peculiar worklosd or requirement[*]. Or their VM
    > > > > > *used* to suck, and the drop_caches is not really needed any more but
    > > > > > it's there in vendor-provided code and they can't practically prevent
    > > > > > it.
    > > > >
    > > > > I have drop_caches in my suspend-to-disk script so that the hibernation
    > > > > image is kept at minimum and suspend times are as small as possible.
    > > >
    > > > hm, that sounds smart.
    > > >
    > > > > Would that be a valid use-case?
    > > >
    > > > I'd say so, unless we change the kernel to do that internally. We do
    > > > have the hibernation-specific shrink_all_memory() in the vmscan code.
    > > > We didn't see fit to document _why_ that exists, but IIRC it's there to
    > > > create enough free memory for hibernation to be able to successfully
    > > > complete, but no more.
    > >
    > > That's correct.
    >
    > Well, my point was: how about the idea of reclaiming clean pagecache
    > (and inodes, dentries, etc) before hibernation so we read/write less
    > disk data?

    We may actually want to write more into the image to improve post-resume
    responsiveness.

    > Given that it's so easy to do from the hibernation script, I guess
    > there's not much point...

    Well, I'd say so. :-)


    --
    I speak only for myself.
    Rafael J. Wysocki, Intel Open Source Technology Center.


    \
     
     \ /
      Last update: 2012-10-25 22:41    [W:4.087 / U:0.520 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site