From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx135.postini.com [74.125.245.135]) by kanga.kvack.org (Postfix) with SMTP id 7060C6B0044 for ; Thu, 18 Oct 2012 20:03:59 -0400 (EDT) Received: by mail-ob0-f169.google.com with SMTP id va7so11115493obc.14 for ; Thu, 18 Oct 2012 17:03:58 -0700 (PDT) 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 Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: 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 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, 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