From: Mike Kravetz <mike.kravetz@oracle.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>,
Mel Gorman <mgorman@suse.de>, Vlastimil Babka <vbabka@suse.cz>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [Question] Should direct reclaim time be bounded?
Date: Thu, 4 Jul 2019 08:11:44 -0700 [thread overview]
Message-ID: <c801da70-1aa5-666a-615e-852100d6145e@oracle.com> (raw)
In-Reply-To: <20190704110903.GE5620@dhcp22.suse.cz>
On 7/4/19 4:09 AM, Michal Hocko wrote:
> On Wed 03-07-19 16:54:35, Mike Kravetz wrote:
>> On 7/3/19 2:43 AM, Mel Gorman wrote:
>>> Indeed. I'm getting knocked offline shortly so I didn't give this the
>>> time it deserves but it appears that part of this problem is
>>> hugetlb-specific when one node is full and can enter into this continual
>>> loop due to __GFP_RETRY_MAYFAIL requiring both nr_reclaimed and
>>> nr_scanned to be zero.
>>
>> Yes, I am not aware of any other large order allocations consistently made
>> with __GFP_RETRY_MAYFAIL. But, I did not look too closely. Michal believes
>> that hugetlb pages allocations should use __GFP_RETRY_MAYFAIL.
>
> Yes. The argument is that this is controlable by an admin and failures
> should be prevented as much as possible. I didn't get to understand
> should_continue_reclaim part of the problem but I have a strong feeling
> that __GFP_RETRY_MAYFAIL handling at that layer is not correct. What
> happens if it is simply removed and we rely only on the retry mechanism
> from the page allocator instead? Does the success rate is reduced
> considerably?
It certainly will be reduced. I 'think' it will be hard to predict how
much it will be reduced as this will depend on the state of memory usage
and fragmentation at the time of the attempt.
I can try to measure this, but I will be a few days due to U.S. holiday.
--
Mike Kravetz
next prev parent reply other threads:[~2019-07-04 15:11 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-23 4:07 [Question] Should direct reclaim time be bounded? Mike Kravetz
2019-04-23 7:19 ` Michal Hocko
2019-04-23 16:39 ` Mike Kravetz
2019-04-24 14:35 ` Vlastimil Babka
2019-06-28 18:20 ` Mike Kravetz
2019-07-01 8:59 ` Mel Gorman
2019-07-02 3:15 ` Mike Kravetz
2019-07-03 9:43 ` Mel Gorman
2019-07-03 23:54 ` Mike Kravetz
2019-07-04 11:09 ` Michal Hocko
2019-07-04 15:11 ` Mike Kravetz [this message]
2019-07-08 5:19 ` Hillf Danton
2019-07-10 18:42 ` Mike Kravetz
2019-07-10 19:44 ` Michal Hocko
2019-07-10 23:36 ` Mike Kravetz
2019-07-11 7:12 ` Michal Hocko
2019-07-12 9:49 ` Mel Gorman
2019-07-11 15:44 Hillf Danton
2019-07-12 5:47 Hillf Danton
2019-07-13 1:11 ` Mike Kravetz
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=c801da70-1aa5-666a-615e-852100d6145e@oracle.com \
--to=mike.kravetz@oracle.com \
--cc=aarcange@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mgorman@techsingularity.net \
--cc=mhocko@kernel.org \
--cc=vbabka@suse.cz \
/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).