Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751150AbWHYHU5 (ORCPT ); Fri, 25 Aug 2006 03:20:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751155AbWHYHU4 (ORCPT ); Fri, 25 Aug 2006 03:20:56 -0400 Received: from relay.2ka.mipt.ru ([194.85.82.65]:8596 "EHLO 2ka.mipt.ru") by vger.kernel.org with ESMTP id S1751150AbWHYHUz (ORCPT ); Fri, 25 Aug 2006 03:20:55 -0400 Date: Fri, 25 Aug 2006 11:20:08 +0400 From: Evgeniy Polyakov To: Andrew Morton Cc: Christoph Hellwig , lkml , David Miller , Ulrich Drepper , netdev , Zach Brown Subject: Re: [take13 1/3] kevent: Core files. Message-ID: <20060825072007.GE1816@2ka.mipt.ru> References: <11563322941645@2ka.mipt.ru> <11563322971212@2ka.mipt.ru> <20060824200322.GA19533@infradead.org> <20060825054815.GC16504@2ka.mipt.ru> <20060824232024.0d230823.akpm@osdl.org> <20060825063238.GD16504@2ka.mipt.ru> <20060824235859.f8840fb2.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20060824235859.f8840fb2.akpm@osdl.org> User-Agent: Mutt/1.5.9i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.7.5 (2ka.mipt.ru [0.0.0.0]); Fri, 25 Aug 2006 11:20:16 +0400 (MSD) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2048 Lines: 53 On Thu, Aug 24, 2006 at 11:58:59PM -0700, Andrew Morton (akpm@osdl.org) wrote: > > > > kmalloc is really slow actually - it always shows somewhere on top > > > > in profiles and brings noticeble overhead > > > > > > It shouldn't. Please describe the workload and send the profiles. > > > > epoll based trivial server (accept + sendfile for the same file, about > > 4k), httperf with big amount of simulateneous connections. 3c59x NIC > > (with e1000 there were no ioreads and netif_rx). > > __alloc_skb calls kmem_cache_alloc() and ___kmalloc(). > > > > 16158 1.3681 ioread16 > > 8073 0.6835 ioread32 > > 3485 0.2951 irq_entries_start > > 3018 0.2555 _spin_lock > > 2103 0.1781 tcp_v4_rcv > > 1503 0.1273 sysenter_past_esp > > 1492 0.1263 netif_rx > > 1459 0.1235 skb_copy_bits > > 1422 0.1204 _spin_lock_irqsave > > 1145 0.0969 ip_route_input > > 983 0.0832 kmem_cache_free > > 964 0.0816 __alloc_skb > > 926 0.0784 common_interrupt > > 891 0.0754 __do_IRQ > > 846 0.0716 _read_lock > > 826 0.0699 __netif_rx_schedule > > 806 0.0682 __kmalloc > > 767 0.0649 do_tcp_sendpages > > 747 0.0632 __copy_to_user_ll > > 744 0.0630 pskb_expand_head > > > > That doesn't look too bad. > > What's that as a percentage of total user+system time? With e1000 allocations take more time than actual TCP processing, so it rised some suspicious for me (especially in bulk transfer). Total time is about 7 times more than system one, user time is much less than system one (about 20 times less, but test duration was not too long, so it can vary). I do not say it is bad, but it is noticeble and should be eliminated if there are no requirements to have it. -- Evgeniy Polyakov - 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/