From: Christopher Lameter <cl@linux.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Mikulas Patocka <mpatocka@redhat.com>,
Mike Snitzer <snitzer@redhat.com>,
Matthew Wilcox <willy@infradead.org>,
Pekka Enberg <penberg@kernel.org>,
linux-mm@kvack.org, dm-devel@redhat.com,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] SLUB: Do not fallback to mininum order if __GFP_NORETRY is set
Date: Fri, 20 Apr 2018 09:53:53 -0500 (CDT) [thread overview]
Message-ID: <alpine.DEB.2.20.1804200952230.18006@nuc-kabylake> (raw)
In-Reply-To: <20180419110051.GB16083@dhcp22.suse.cz>
On Thu, 19 Apr 2018, Michal Hocko wrote:
> Overriding __GFP_NORETRY is just a bad idea. It will make the semantic
> of the flag just more confusing. Note there are users who use
> __GFP_NORETRY as a way to suppress heavy memory pressure and/or the OOM
> killer. You do not want to change the semantic for them.
Redoing the allocation after failing a large order alloc is a retry. I
would say its confusing right now because a retry occurs despite
specifying GFP_NORETRY,
> Besides that the changelog is less than optimal. What is the actual
> problem? Why somebody doesn't want a fallback? Is there a configuration
> that could prevent the same?
The problem is that SLUB does not honor GFP_NORETRY. The semantics of
GFP_NORETRY are not followed.
next prev parent reply other threads:[~2018-04-20 14:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-18 14:45 Christopher Lameter
2018-04-18 15:05 ` Mikulas Patocka
2018-04-18 15:11 ` Christopher Lameter
2018-04-18 18:49 ` David Rientjes
2018-04-19 11:00 ` Michal Hocko
2018-04-20 14:53 ` Christopher Lameter [this message]
2018-04-21 17:02 ` Vlastimil Babka
2018-04-23 22:41 ` Christopher Lameter
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