linux-kernel - Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1481137249.4930.59.camel@edumazet-glaptop3.roam.corp.google.com>
Date:   Wed, 07 Dec 2016 11:00:49 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     Mel Gorman <mgorman@...hsingularity.net>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Christoph Lameter <cl@...ux.com>,
        Michal Hocko <mhocko@...e.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Johannes Weiner <hannes@...xchg.org>,
        Jesper Dangaard Brouer <brouer@...hat.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Linux-MM <linux-mm@...ck.org>,
        Linux-Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7

On Wed, 2016-12-07 at 10:12 +0000, Mel Gorman wrote:

> This is the result from netperf running UDP_STREAM on localhost. It was
> selected on the basis that it is slab-intensive and has been the subject
> of previous SLAB vs SLUB comparisons with the caveat that this is not
> testing between two physical hosts.
> 

Interesting results.

netperf UDP_STREAM is not really slab intensive : (for large sendsizes
like 16KB)

Bulk of the storage should be allocated from alloc_skb_with_frags(),
ie using pages.

And I am not sure we enabled high order pages in this path ?

ip_make_skb()
 __ip_append_data()
  sock_alloc_send_skb()
   sock_alloc_send_pskb (...,  max_page_order=0)
    alloc_skb_with_frags ( max_page_order=0)
 
So far, I believe net/unix/af_unix.c uses PAGE_ALLOC_COSTLY_ORDER as
max_order, but UDP does not do that yet.

We probably could enable high-order pages there, if we believe this is
okay.

Or maybe I missed and this already happened ? ;)

Thanks.