From: Hugh Dickins <hughd@google.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Hugh Dickins <hughd@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Andres Lagar-Cavilla <andreslc@google.com>,
Yang Shi <yang.shi@linaro.org>, Ning Qu <quning@gmail.com>,
Ralf Baechle <ralf@linux-mips.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
David Miller <davem@davemloft.net>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [PATCH 12/31] huge tmpfs: extend get_user_pages_fast to shmem pmd
Date: Wed, 6 Apr 2016 19:53:57 -0700 (PDT) [thread overview]
Message-ID: <alpine.LSU.2.11.1604061917530.3092@eggly.anvils> (raw)
In-Reply-To: <20160406070044.GD3078@gmail.com>
On Wed, 6 Apr 2016, Ingo Molnar wrote:
> * Hugh Dickins <hughd@google.com> wrote:
>
> > ---
> > Cc'ed to arch maintainers as an FYI: this patch is not expected to
> > go into the tree in the next few weeks, and depends upon a PageTeam
> > definition not yet available outside this huge tmpfs patchset.
> > Please refer to linux-mm or linux-kernel for more context.
Actually, Andrew took it and the rest into mmotm yesterday, to give them
better exposure through linux-next, so they should appear there soon.
> >
> > arch/mips/mm/gup.c | 15 ++++++++++++++-
> > arch/s390/mm/gup.c | 19 ++++++++++++++++++-
> > arch/sparc/mm/gup.c | 19 ++++++++++++++++++-
> > arch/x86/mm/gup.c | 15 ++++++++++++++-
> > mm/gup.c | 19 ++++++++++++++++++-
> > 5 files changed, 82 insertions(+), 5 deletions(-)
...
>
> Ouch!
Oh sorry, I didn't mean to hurt you ;)
>
> Looks like there are two main variants - so these kinds of repetitive patterns
> very much call for some sort of factoring out of common code, right?
Hmm. I'm still struggling between the two extremes, of
(a) agreeing completely with you, and saying, yeah, I'll take on the job
of refactoring every architecture's get_user_pages_as_fast_as_you_can(),
without much likelihood of testing more than one,
and
(b) running a mile, and pointing out that we have a tradition of using
arch/x86/mm/gup.c as a template for the others, and here I've just
added a few more lines to that template (which never gets built more
than once into any kernel).
Both are appealing in their different ways, but I think you can tell
which I'm leaning towards...
Honestly, I am still struggling between those two; but I think the patch
as it stands is one thing, and cleanup for commonality should be another
however weaselly that sounds ("I'll come back to it" - yeah, right).
Hugh
>
> Then the fix could be applied to the common portion(s) only, which will cut down
> this gigantic diffstat:
>
> > 5 files changed, 82 insertions(+), 5 deletions(-)
>
> Thanks,
>
> Ingo
next prev parent reply other threads:[~2016-04-07 2:54 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 21:10 [PATCH 00/31] huge tmpfs: THPagecache implemented by teams Hugh Dickins
2016-04-05 21:12 ` [PATCH 01/31] huge tmpfs: prepare counts in meminfo, vmstat and SysRq-m Hugh Dickins
2016-04-11 11:05 ` Kirill A. Shutemov
2016-04-17 2:28 ` Hugh Dickins
2016-04-05 21:13 ` [PATCH 02/31] huge tmpfs: include shmem freeholes in available memory Hugh Dickins
2016-04-05 21:15 ` [PATCH 03/31] huge tmpfs: huge=N mount option and /proc/sys/vm/shmem_huge Hugh Dickins
2016-04-11 11:17 ` Kirill A. Shutemov
2016-04-17 2:00 ` Hugh Dickins
2016-04-05 21:16 ` [PATCH 04/31] huge tmpfs: try to allocate huge pages, split into a team Hugh Dickins
2016-04-05 21:17 ` [PATCH 05/31] huge tmpfs: avoid team pages in a few places Hugh Dickins
2016-04-05 21:20 ` [PATCH 06/31] huge tmpfs: shrinker to migrate and free underused holes Hugh Dickins
2016-04-05 21:21 ` [PATCH 07/31] huge tmpfs: get_unmapped_area align & fault supply huge page Hugh Dickins
2016-04-05 21:23 ` [PATCH 08/31] huge tmpfs: try_to_unmap_one use page_check_address_transhuge Hugh Dickins
2016-04-05 21:24 ` [PATCH 09/31] huge tmpfs: avoid premature exposure of new pagetable Hugh Dickins
2016-04-11 11:54 ` Kirill A. Shutemov
2016-04-17 1:49 ` Hugh Dickins
2016-04-05 21:25 ` [PATCH 10/31] huge tmpfs: map shmem by huge page pmd or by page team ptes Hugh Dickins
2016-04-05 21:29 ` [PATCH 11/31] huge tmpfs: disband split huge pmds on race or memory failure Hugh Dickins
2016-04-05 21:33 ` [PATCH 12/31] huge tmpfs: extend get_user_pages_fast to shmem pmd Hugh Dickins
2016-04-06 7:00 ` Ingo Molnar
2016-04-07 2:53 ` Hugh Dickins [this message]
2016-04-13 8:58 ` Ingo Molnar
2016-04-05 21:34 ` [PATCH 13/31] huge tmpfs: use Unevictable lru with variable hpage_nr_pages Hugh Dickins
2016-04-05 21:35 ` [PATCH 14/31] huge tmpfs: fix Mlocked meminfo, track huge & unhuge mlocks Hugh Dickins
2016-04-05 21:37 ` [PATCH 15/31] huge tmpfs: fix Mapped meminfo, track huge & unhuge mappings Hugh Dickins
2016-04-05 21:39 ` [PATCH 16/31] kvm: plumb return of hva when resolving page fault Hugh Dickins
2016-04-05 21:41 ` [PATCH 17/31] kvm: teach kvm to map page teams as huge pages Hugh Dickins
2016-04-05 23:37 ` Paolo Bonzini
2016-04-06 1:12 ` Hugh Dickins
2016-04-06 6:47 ` Paolo Bonzini
2016-04-05 21:44 ` [PATCH 18/31] huge tmpfs: mem_cgroup move charge on shmem " Hugh Dickins
2016-04-05 21:46 ` [PATCH 19/31] huge tmpfs: mem_cgroup shmem_pmdmapped accounting Hugh Dickins
2016-04-05 21:47 ` [PATCH 20/31] huge tmpfs: mem_cgroup shmem_hugepages accounting Hugh Dickins
2016-04-05 21:49 ` [PATCH 21/31] huge tmpfs: show page team flag in pageflags Hugh Dickins
2016-04-05 21:51 ` [PATCH 22/31] huge tmpfs: /proc/<pid>/smaps show ShmemHugePages Hugh Dickins
2016-04-05 21:53 ` [PATCH 23/31] huge tmpfs recovery: framework for reconstituting huge pages Hugh Dickins
2016-04-06 10:28 ` Mika Penttilä
2016-04-07 2:05 ` Hugh Dickins
2016-04-05 21:54 ` [PATCH 24/31] huge tmpfs recovery: shmem_recovery_populate to fill huge page Hugh Dickins
2016-04-05 21:56 ` [PATCH 25/31] huge tmpfs recovery: shmem_recovery_remap & remap_team_by_pmd Hugh Dickins
2016-04-05 21:58 ` [PATCH 26/31] huge tmpfs recovery: shmem_recovery_swapin to read from swap Hugh Dickins
2016-04-05 22:00 ` [PATCH 27/31] huge tmpfs recovery: tweak shmem_getpage_gfp to fill team Hugh Dickins
2016-04-05 22:02 ` [PATCH 28/31] huge tmpfs recovery: debugfs stats to complete this phase Hugh Dickins
2016-04-05 22:03 ` [PATCH 29/31] huge tmpfs recovery: page migration call back into shmem Hugh Dickins
2016-04-05 22:05 ` [PATCH 30/31] huge tmpfs: shmem_huge_gfpmask and shmem_recovery_gfpmask Hugh Dickins
2016-04-05 22:07 ` [PATCH 31/31] huge tmpfs: no kswapd by default on sync allocations Hugh Dickins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.LSU.2.11.1604061917530.3092@eggly.anvils \
--to=hughd@google.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andreslc@google.com \
--cc=davem@davemloft.net \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@kernel.org \
--cc=quning@gmail.com \
--cc=ralf@linux-mips.org \
--cc=schwidefsky@de.ibm.com \
--cc=yang.shi@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).