From: Shakeel Butt <shakeelb@google.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>,
Eric Dumazet <edumazet@google.com>,
Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH 7/9] net: use kvmalloc with __GFP_REPEAT rather than open coded variant
Date: Thu, 30 Mar 2017 16:21:43 -0700 [thread overview]
Message-ID: <CALvZod73-ddnbMAWXF9QpXMcpjZMLreLXheUo-CgcB7s_5iBnQ@mail.gmail.com> (raw)
In-Reply-To: <20170306103327.2766-3-mhocko@kernel.org>
On Mon, Mar 6, 2017 at 2:33 AM, Michal Hocko <mhocko@kernel.org> wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> fq_alloc_node, alloc_netdev_mqs and netif_alloc* open code kmalloc
> with vmalloc fallback. Use the kvmalloc variant instead. Keep the
> __GFP_REPEAT flag based on explanation from Eric:
> "
> At the time, tests on the hardware I had in my labs showed that
> vmalloc() could deliver pages spread all over the memory and that was a
> small penalty (once memory is fragmented enough, not at boot time)
> "
>
> The way how the code is constructed means, however, that we prefer to go
> and hit the OOM killer before we fall back to the vmalloc for requests
> <=32kB (with 4kB pages) in the current code. This is rather disruptive for
> something that can be achived with the fallback. On the other hand
> __GFP_REPEAT doesn't have any useful semantic for these requests. So the
> effect of this patch is that requests smaller than 64kB will fallback to
I am a bit confused about this 64kB, shouldn't it be <=32kB (with 4kB
pages & PAGE_ALLOC_COSTLY_ORDER = 3)?
> vmalloc easier now.
>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: netdev@vger.kernel.org
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
> ---
next prev parent reply other threads:[~2017-03-30 23:22 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-06 10:30 [PATCH 0/6 v5] kvmalloc Michal Hocko
2017-03-06 10:30 ` [PATCH 1/9] mm: introduce kv[mz]alloc helpers Michal Hocko
2017-06-02 7:17 ` Levin, Alexander (Sasha Levin)
2017-06-02 7:28 ` Michal Hocko
2017-06-02 7:40 ` Levin, Alexander (Sasha Levin)
2017-06-02 7:50 ` Michal Hocko
2017-03-06 10:30 ` [PATCH 2/9] mm: support __GFP_REPEAT in kvmalloc_node for >32kB Michal Hocko
2017-04-07 0:45 ` Shakeel Butt
2017-04-07 7:40 ` Michal Hocko
2017-03-06 10:30 ` [PATCH 3/9] rhashtable: simplify a strange allocation pattern Michal Hocko
2017-03-06 10:30 ` [PATCH 4/9] ila: " Michal Hocko
2017-03-06 10:33 ` [PATCH 5/9] xattr: zero out memory copied to userspace in getxattr Michal Hocko
2017-03-06 10:33 ` [PATCH 6/9] treewide: use kv[mz]alloc* rather than opencoded variants Michal Hocko
2017-03-06 10:33 ` [PATCH 7/9] net: use kvmalloc with __GFP_REPEAT rather than open coded variant Michal Hocko
2017-03-30 23:21 ` Shakeel Butt [this message]
2017-03-31 8:46 ` Michal Hocko
2017-03-06 10:33 ` [PATCH 8/9] md: use kvmalloc rather than opencoded variant Michal Hocko
2017-03-06 10:33 ` [PATCH 9/9] bcache: use kvmalloc Michal Hocko
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