From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758044Ab3BRGSa (ORCPT ); Mon, 18 Feb 2013 01:18:30 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:25859 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752862Ab3BRGS2 convert rfc822-to-8bit (ORCPT ); Mon, 18 Feb 2013 01:18:28 -0500 X-IronPort-AV: E=Sophos;i="4.84,685,1355068800"; d="scan'208";a="6721919" Message-ID: <5121C699.2050408@cn.fujitsu.com> Date: Mon, 18 Feb 2013 14:13:45 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.8) Gecko/20121012 Thunderbird/10.0.8 MIME-Version: 1.0 To: Julian Anastasov CC: Andrew Morton , davem@davemloft.net, Simon Horman , Linux MM , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] net: fix functions and variables related to netns_ipvs->sysctl_sync_qlen_max References: <51131B88.6040809@cn.fujitsu.com> <51132A56.60906@cn.fujitsu.com> <20130214142159.d0516a5f.akpm@linux-foundation.org> In-Reply-To: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/02/18 14:14:38, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/02/18 14:14:39 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 于 2013年02月16日 05:39, Julian Anastasov 写道: > > Hello, > > On Thu, 14 Feb 2013, Andrew Morton wrote: > >> On Thu, 7 Feb 2013 10:40:26 +0200 (EET) >> Julian Anastasov wrote: >> >>>> Another question about the sysctl_sync_qlen_max: >>>> This variable is assigned as: >>>> >>>> ipvs->sysctl_sync_qlen_max = nr_free_buffer_pages() / 32; >>>> >>>> The function nr_free_buffer_pages actually means: counts of pages >>>> which are beyond high watermark within ZONE_DMA and ZONE_NORMAL. >>>> >>>> is it ok to be called here? Some people misused this function because >>>> the function name was misleading them. I am sorry I am totally not >>>> familiar with the ipvs code, so I am just asking you about >>>> this. >>> >>> Using nr_free_buffer_pages should be fine here. >>> We are using it as rough estimation for the number of sync >>> buffers we can use in NORMAL zones. We are using dev->mtu >>> for such buffers, so it can take a PAGE_SIZE for a buffer. >>> We are not interested in HIGHMEM size. high watermarks >>> should have negliable effect. I'm even not sure whether >>> we need to clamp it for systems with TBs of memory. >> >> Using nr_free_buffer_pages() is good-enough-for-now. There are >> questions around the name of this thing and its exact functionality and >> whether callers are using it appropriately. But if anything is changed >> there, it will be as part of kernel-wide sweep. >> >> One thing to bear in mind is memory hot[un]plug. Anything which was >> sized using nr_free_buffer_pages() (or similar) may become >> inappropriately sized if memory is added or removed. So any site which >> uses nr_free_buffer_pages() really should be associated with a hotplug >> handler and a great pile of code to resize the structure at runtime. >> It's pretty ugly stuff :( I suspect it usually Just Doesn't Matter. > > I'll try to think on this hotplug problem > and also on the si_meminfo usage in net/netfilter/ipvs/ip_vs_ctl.c > which is quite wrong for systems with HIGHMEM, may be > we need there a free+reclaimable+file function for > NORMAL zone. > >> Redarding this patch: >> net-change-type-of-netns_ipvs-sysctl_sync_qlen_max.patch and >> net-fix-functions-and-variables-related-to-netns_ipvs-sysctl_sync_qlen_max.patch >> are joined at the hip and should be redone as a single patch with a >> suitable changelog, please. And with a cc:netdev@vger.kernel.org. > > Agreed, Zhang Yanfei and Simon? I'm just not sure, > may be this combined patch should hit only the > ipvs->nf->net trees? Or may be net-next, if we don't have > time for 3.8. > Should I resend the combined patch?