lkml.org 
[lkml]   [2012]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Fwd: Control page reclaim granularity
    On Tue, Mar 13, 2012 at 01:17:41PM +0530, Kautuk Consul wrote:
    > On Tue, Mar 13, 2012 at 1:13 PM, Kautuk Consul <consul.kautuk@gmail.com> wrote:
    > > Hi,
    > >
    > > I noticed this discussion and decided to pitch in one small idea from my side.
    > >
    > > It would be nice to range lock an inode's pages by storing those
    > > ranges which would be locked.
    > > This could also add some good routines for the kernel in terms of
    > > range locking for a single inode.
    > > However, wouldn't this add some overhead to shrink_page_list() since
    > > that code would need to go through
    > > all these ranges while trying to reclaim a single page ?
    > >
    > > One small suggestion from my side is:
    > > Why don't we implement something like : "Complete page-cache reclaim
    > > control from usermode"?
    > > In this, we can set/unset the mapping to AS_UNEVICTABLE (as Konstantin
    > > mentioned) for a file's
    > > inode from usermode by using ioctl or fcntl or maybe even go as far as
    > > implementing an O_NORECL
    > > option to the open system call.
    > >
    >
    > Of course, only an application executing with root privileges should
    > be allowed to set the inode's
    > mapping flags in this manner.

    Hi Kautuk,

    IMHO, running application with root privilege is too dangerous. We
    should avoid it.

    Regards,
    Zheng

    >
    >
    > > After setting the AS_UNEVICTABLE, the usermode application can choose
    > > to keep and remove pages by
    > > using the fadvise(WILLNEED) and fadvise(DONTNEED).
    > >
    > > ( I think maybe the presence of any VMA is might not really be
    > > required for this idea. )
    > >
    > > Thanks,
    > > Kautuk.
    >
    > --
    > To unsubscribe, send a message with 'unsubscribe linux-mm' in
    > the body to majordomo@kvack.org. For more info on Linux MM,
    > see: http://www.linux-mm.org/ .
    > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
    > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>


    \
     
     \ /
      Last update: 2012-03-13 09:03    [W:0.023 / U:29.680 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site