From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx149.postini.com [74.125.245.149]) by kanga.kvack.org (Postfix) with SMTP id 44B3E6B0044 for ; Sat, 13 Oct 2012 05:54:52 -0400 (EDT) Received: by mail-da0-f41.google.com with SMTP id i14so2002819dad.14 for ; Sat, 13 Oct 2012 02:54:51 -0700 (PDT) Date: Sat, 13 Oct 2012 02:54:49 -0700 (PDT) From: David Rientjes Subject: Re: [Q] Default SLAB allocator In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Ezequiel Garcia Cc: Andi Kleen , Linux Kernel Mailing List , linux-mm@kvack.org, Tim Bird , celinux-dev@lists.celinuxforum.org On Fri, 12 Oct 2012, Ezequiel Garcia wrote: > >> SLUB is a non-starter for us and incurs a >10% performance degradation in > >> netperf TCP_RR. > > > > Where are you seeing that? > In my benchmarking results. > Notice that many defconfigs are for embedded devices, > and many of them say "use SLAB"; I wonder if that's right. > If a device doesn't require the smallest memory footprint possible (SLOB) then SLAB is the right choice when there's a limited amount of memory; SLUB requires higher order pages for the best performance (on my desktop system running with CONFIG_SLUB, over 50% of the slab caches default to be high order). > Is there any intention to replace SLAB by SLUB? There may be an intent, but it'll be nacked as long as there's a performance degradation. > In that case it could make sense to change defconfigs, although > it wouldn't be based on any actual tests. > Um, you can't just go changing defconfigs without doing some due diligence in ensuring it won't be deterimental for those users. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org