From: Michal Hocko <mhocko@kernel.org>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
David Rientjes <rientjes@google.com>,
Mel Gorman <mgorman@suse.de>,
Johannes Weiner <hannes@cmpxchg.org>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Anatoly Stepanov <astepanov@cloudlinux.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Mike Snitzer <snitzer@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Theodore Ts'o" <tytso@mit.edu>
Subject: Re: [PATCH 1/6] mm: introduce kv[mz]alloc helpers
Date: Mon, 16 Jan 2017 20:40:53 +0100 [thread overview]
Message-ID: <20170116194052.GA9382@dhcp22.suse.cz> (raw)
In-Reply-To: <0ca8a212-c651-7915-af25-23925e1c1cc3@nvidia.com>
On Mon 16-01-17 11:09:37, John Hubbard wrote:
>
>
> On 01/16/2017 12:47 AM, Michal Hocko wrote:
> > On Sun 15-01-17 20:34:13, John Hubbard wrote:
[...]
> > > Is that "Reclaim modifiers" line still true, or is it a leftover from an
> > > earlier approach? I am having trouble reconciling it with rest of the
> > > patchset, because:
> > >
> > > a) the flags argument below is effectively passed on to either kmalloc_node
> > > (possibly adding, but not removing flags), or to __vmalloc_node_flags.
> >
> > The above only says thos are _unsupported_ - in other words the behavior
> > is not defined. Even if flags are passed down to kmalloc resp. vmalloc
> > it doesn't mean they are used that way. Remember that vmalloc uses
> > some hardcoded GFP_KERNEL allocations. So while I could be really
> > strict about this and mask away these flags I doubt this is worth the
> > additional code.
>
> I do wonder about passing those flags through to kmalloc. Maybe it is worth
> stripping out __GFP_NORETRY and __GFP_NOFAIL, after all. It provides some
> insulation from any future changes to the implementation of kmalloc, and it
> also makes the documentation more believable.
I am not really convinced that we should take an extra steps for these
flags. There are no existing users for those flags and new users should
follow the documentation.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2017-01-16 19:41 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-12 15:37 [PATCH 0/6 v3] kvmalloc Michal Hocko
2017-01-12 15:37 ` [PATCH 1/6] mm: introduce kv[mz]alloc helpers Michal Hocko
2017-01-16 4:34 ` John Hubbard
2017-01-16 8:47 ` Michal Hocko
2017-01-16 19:09 ` John Hubbard
2017-01-16 19:40 ` Michal Hocko [this message]
2017-01-16 21:15 ` John Hubbard
2017-01-16 21:48 ` Michal Hocko
2017-01-16 21:57 ` John Hubbard
2017-01-17 7:51 ` Michal Hocko
2017-01-18 5:59 ` John Hubbard
2017-01-18 8:21 ` Michal Hocko
2017-01-19 8:37 ` John Hubbard
2017-01-19 8:45 ` Michal Hocko
2017-01-19 9:09 ` John Hubbard
2017-01-19 9:56 ` Michal Hocko
2017-01-19 21:28 ` John Hubbard
2017-01-26 12:09 ` Michal Hocko
2017-01-30 8:42 ` Vlastimil Babka
2017-01-12 15:37 ` [PATCH 2/6] mm: support __GFP_REPEAT in kvmalloc_node for >=64kB Michal Hocko
2017-01-12 16:12 ` Michael S. Tsirkin
2017-01-14 2:42 ` Tetsuo Handa
2017-01-14 8:45 ` Michal Hocko
2017-01-24 15:40 ` Michael S. Tsirkin
2017-01-12 15:37 ` [PATCH 3/6] rhashtable: simplify a strange allocation pattern Michal Hocko
2017-01-12 15:37 ` [PATCH 4/6] ila: " Michal Hocko
2017-01-12 15:37 ` [PATCH 5/6] treewide: use kv[mz]alloc* rather than opencoded variants Michal Hocko
2017-01-12 15:57 ` David Sterba
2017-01-12 16:05 ` Christian Borntraeger
2017-01-12 16:54 ` Ilya Dryomov
2017-01-12 17:18 ` Michal Hocko
2017-01-12 17:00 ` Dan Williams
2017-01-12 17:26 ` Kees Cook
2017-01-12 17:37 ` Michal Hocko
2017-01-20 13:41 ` Vlastimil Babka
2017-01-24 15:00 ` Michal Hocko
2017-01-25 11:15 ` Vlastimil Babka
2017-01-25 13:09 ` Michal Hocko
2017-01-25 13:40 ` Ilya Dryomov
2017-01-12 17:29 ` Michal Hocko
2017-01-14 3:01 ` Tetsuo Handa
2017-01-14 8:49 ` Michal Hocko
2017-01-12 20:14 ` Boris Ostrovsky
2017-01-13 1:11 ` Dilger, Andreas
2017-01-14 10:56 ` Leon Romanovsky
2017-01-16 7:33 ` Michal Hocko
2017-01-16 8:28 ` Leon Romanovsky
2017-01-16 8:18 ` Tariq Toukan
2017-01-12 15:37 ` [RFC PATCH 6/6] net: use kvmalloc with __GFP_REPEAT rather than open coded variant Michal Hocko
2017-01-24 15:17 ` [PATCH 0/6 v3] kvmalloc Michal Hocko
2017-01-24 16:00 ` Eric Dumazet
2017-01-25 13:10 ` Michal Hocko
2017-01-24 19:17 ` Alexei Starovoitov
2017-01-25 13:10 ` Michal Hocko
2017-01-25 13:21 ` Michal Hocko
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