lkml.org 
[lkml]   [2017]   [Apr]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] mm, zone_device: replace {get, put}_zone_device_page() with a single reference

    * Kirill A. Shutemov <kirill@shutemov.name> wrote:

    > On Wed, Apr 26, 2017 at 05:55:31PM -0700, Dan Williams wrote:
    > > Kirill points out that the calls to {get,put}_dev_pagemap() can be
    > > removed from the mm fast path if we take a single get_dev_pagemap()
    > > reference to signify that the page is alive and use the final put of the
    > > page to drop that reference.
    > >
    > > This does require some care to make sure that any waits for the
    > > percpu_ref to drop to zero occur *after* devm_memremap_page_release(),
    > > since it now maintains its own elevated reference.
    > >
    > > Cc Ingo Molnar <mingo@redhat.com>
    > > Cc: Jérôme Glisse <jglisse@redhat.com>
    > > Cc: Logan Gunthorpe <logang@deltatee.com>
    > > Cc: Andrew Morton <akpm@linux-foundation.org>
    > > Suggested-by: Kirill Shutemov <kirill.shutemov@linux.intel.com>
    > > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
    > > ---
    > >
    > > This patch might fix the regression that we found with the conversion to
    > > generic get_user_pages_fast() in the x86/mm branch pending for 4.12
    > > (commit 2947ba054a4d "x86/mm/gup: Switch GUP to the generic
    > > get_user_page_fast() implementation"). I'll test tomorrow, but in case
    > > someone can give it a try before I wake up, here's an early version.
    >
    > + Ingo.
    >
    > This works for me with and without GUP revert.
    >
    > Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
    >
    > > drivers/dax/pmem.c | 2 +-
    > > drivers/nvdimm/pmem.c | 13 +++++++++++--
    >
    > There's a trivial conflict in drivers/nvdimm/pmem.c when applied to
    > tip/master.

    Ok, could someone please send a version either to Linus for v4.11, or a version
    against latest -tip so I can included it in x86/mm, so that x86/mm gets unbroken.

    Thanks,

    Ingo

    \
     
     \ /
      Last update: 2017-04-28 08:39    [W:9.470 / U:0.232 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site