From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752237AbbKKQHh (ORCPT ); Wed, 11 Nov 2015 11:07:37 -0500 Received: from mx2.parallels.com ([199.115.105.18]:57806 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750961AbbKKQHf (ORCPT ); Wed, 11 Nov 2015 11:07:35 -0500 Date: Wed, 11 Nov 2015 19:07:19 +0300 From: Vladimir Davydov To: Tejun Heo CC: Andrew Morton , Johannes Weiner , Michal Hocko , Greg Thelen , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , , , Subject: Re: [PATCH v2 4/6] slab: add SLAB_ACCOUNT flag Message-ID: <20151111160719.GX31308@esperanza> References: <1ce23e932ea53f47a3376de90b21a9db8293bd6c.1447172835.git.vdavydov@virtuozzo.com> <20151110183808.GB13740@mtj.duckdns.org> <20151110185401.GW31308@esperanza> <20151111155450.GB6246@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20151111155450.GB6246@mtj.duckdns.org> X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To US-EXCH2.sw.swsoft.com (10.255.249.46) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 11, 2015 at 10:54:50AM -0500, Tejun Heo wrote: > Hello, > > On Tue, Nov 10, 2015 at 09:54:01PM +0300, Vladimir Davydov wrote: > > > Am I correct in thinking that we should eventually be able to removed > > > __GFP_ACCOUNT and that only caches explicitly marked with SLAB_ACCOUNT > > > would need to be handled by kmemcg? > > > > Don't think so, because sometimes we want to account kmalloc. > > I'm kinda skeptical about that because if those allocations are > occassional by nature, we don't care and if there can be a huge number > of them, splitting them into a separate cache makes sense. I think it > makes sense to pin down exactly which caches are memcg managed. That > has the potential to simplify the involved code path and shave off a > small bit of hot path overhead. What about external_name allocation in __d_alloc? Is it occasional? Depends on the workload I guess. Can we create a separate cache for it? No, because its size is variable. There are other things like that, e.g. pipe_buffer array. Thanks, Vladimir From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f46.google.com (mail-pa0-f46.google.com [209.85.220.46]) by kanga.kvack.org (Postfix) with ESMTP id 319006B0253 for ; Wed, 11 Nov 2015 11:07:36 -0500 (EST) Received: by pasz6 with SMTP id z6so35692595pas.2 for ; Wed, 11 Nov 2015 08:07:35 -0800 (PST) Received: from mx2.parallels.com (mx2.parallels.com. [199.115.105.18]) by mx.google.com with ESMTPS id ga3si13507224pbb.56.2015.11.11.08.07.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Nov 2015 08:07:35 -0800 (PST) Date: Wed, 11 Nov 2015 19:07:19 +0300 From: Vladimir Davydov Subject: Re: [PATCH v2 4/6] slab: add SLAB_ACCOUNT flag Message-ID: <20151111160719.GX31308@esperanza> References: <1ce23e932ea53f47a3376de90b21a9db8293bd6c.1447172835.git.vdavydov@virtuozzo.com> <20151110183808.GB13740@mtj.duckdns.org> <20151110185401.GW31308@esperanza> <20151111155450.GB6246@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20151111155450.GB6246@mtj.duckdns.org> Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Greg Thelen , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org On Wed, Nov 11, 2015 at 10:54:50AM -0500, Tejun Heo wrote: > Hello, > > On Tue, Nov 10, 2015 at 09:54:01PM +0300, Vladimir Davydov wrote: > > > Am I correct in thinking that we should eventually be able to removed > > > __GFP_ACCOUNT and that only caches explicitly marked with SLAB_ACCOUNT > > > would need to be handled by kmemcg? > > > > Don't think so, because sometimes we want to account kmalloc. > > I'm kinda skeptical about that because if those allocations are > occassional by nature, we don't care and if there can be a huge number > of them, splitting them into a separate cache makes sense. I think it > makes sense to pin down exactly which caches are memcg managed. That > has the potential to simplify the involved code path and shave off a > small bit of hot path overhead. What about external_name allocation in __d_alloc? Is it occasional? Depends on the workload I guess. Can we create a separate cache for it? No, because its size is variable. There are other things like that, e.g. pipe_buffer array. Thanks, Vladimir -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH v2 4/6] slab: add SLAB_ACCOUNT flag Date: Wed, 11 Nov 2015 19:07:19 +0300 Message-ID: <20151111160719.GX31308@esperanza> References: <1ce23e932ea53f47a3376de90b21a9db8293bd6c.1447172835.git.vdavydov@virtuozzo.com> <20151110183808.GB13740@mtj.duckdns.org> <20151110185401.GW31308@esperanza> <20151111155450.GB6246@mtj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20151111155450.GB6246-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Greg Thelen , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Wed, Nov 11, 2015 at 10:54:50AM -0500, Tejun Heo wrote: > Hello, > > On Tue, Nov 10, 2015 at 09:54:01PM +0300, Vladimir Davydov wrote: > > > Am I correct in thinking that we should eventually be able to removed > > > __GFP_ACCOUNT and that only caches explicitly marked with SLAB_ACCOUNT > > > would need to be handled by kmemcg? > > > > Don't think so, because sometimes we want to account kmalloc. > > I'm kinda skeptical about that because if those allocations are > occassional by nature, we don't care and if there can be a huge number > of them, splitting them into a separate cache makes sense. I think it > makes sense to pin down exactly which caches are memcg managed. That > has the potential to simplify the involved code path and shave off a > small bit of hot path overhead. What about external_name allocation in __d_alloc? Is it occasional? Depends on the workload I guess. Can we create a separate cache for it? No, because its size is variable. There are other things like that, e.g. pipe_buffer array. Thanks, Vladimir