Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757387Ab2JSAEA (ORCPT ); Thu, 18 Oct 2012 20:04:00 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:35275 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751305Ab2JSAD7 (ORCPT ); Thu, 18 Oct 2012 20:03:59 -0400 MIME-Version: 1.0 In-Reply-To: <1350141021.21172.14949.camel@edumazet-glaptop> References: <1350141021.21172.14949.camel@edumazet-glaptop> Date: Fri, 19 Oct 2012 09:03:58 +0900 Message-ID: Subject: Re: [Q] Default SLAB allocator From: JoonSoo Kim To: Eric Dumazet Cc: David Rientjes , Andi Kleen , Ezequiel Garcia , Linux Kernel Mailing List , linux-mm@kvack.org, Tim Bird , celinux-dev@lists.celinuxforum.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1101 Lines: 28 Hello, Eric. Thank you very much for a kind comment about my question. I have one more question related to network subsystem. Please let me know what I misunderstand. 2012/10/14 Eric Dumazet : > In latest kernels, skb->head no longer use kmalloc()/kfree(), so SLAB vs > SLUB is less a concern for network loads. > > In 3.7, (commit 69b08f62e17) we use fragments of order-3 pages to > populate skb->head. You mentioned that in latest kernel skb->head no longer use kmalloc()/kfree(). But, why result of David's "netperf RR" test on v3.6 is differentiated by choosing the allocator? As far as I know, __netdev_alloc_frag may be introduced in v3.5, so I'm just confused. Does this test use __netdev_alloc_skb with "__GFP_WAIT | GFP_DMA"? Does normal workload for network use __netdev_alloc_skb with "__GFP_WAIT | GFP_DMA"? Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/