From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f45.google.com (mail-wg0-f45.google.com [74.125.82.45]) by kanga.kvack.org (Postfix) with ESMTP id DCBCA6B0038 for ; Tue, 22 Apr 2014 08:04:38 -0400 (EDT) Received: by mail-wg0-f45.google.com with SMTP id l18so3750374wgh.28 for ; Tue, 22 Apr 2014 05:04:38 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id e20si13829316wjq.66.2014.04.22.05.04.36 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 22 Apr 2014 05:04:37 -0700 (PDT) Date: Tue, 22 Apr 2014 14:04:32 +0200 From: Michal Hocko Subject: Re: + slub-fix-memcg_propagate_slab_attrs.patch added to -mm tree Message-ID: <20140422120432.GL29311@dhcp22.suse.cz> References: <53518631.cuNCoAbpOk1NRWDf%akpm@linux-foundation.org> <20140422103051.GH29311@dhcp22.suse.cz> <53564A09.3090008@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53564A09.3090008@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: To: Vladimir Davydov Cc: mm-commits@vger.kernel.org, penberg@kernel.org, hannes@cmpxchg.org, cl@linux.com, linux-mm@kvack.org, Andrew Morton On Tue 22-04-14 14:52:57, Vladimir Davydov wrote: > On 04/22/2014 02:30 PM, Michal Hocko wrote: > > On Fri 18-04-14 13:08:17, Andrew Morton wrote: > > [...] > >> From: Vladimir Davydov > >> Subject: slub: fix memcg_propagate_slab_attrs > >> > >> After creating a cache for a memcg we should initialize its sysfs attrs > >> with the values from its parent. That's what memcg_propagate_slab_attrs > >> is for. Currently it's broken - we clearly muddled root-vs-memcg caches > >> there. Let's fix it up. > > > > Andrew didn't so I'll do. What is the effect of the mismatch? I am > > really drowning in that code... > > If we tune a kmem cache's params via sysfs and then create a memcg that > wants to allocate from the cache, the memcg's copy of the cache will > have default values of the sysfs params instead of those of the global > cache. Ahh, ok, I see. Thanks for the clarification. > >> Signed-off-by: Vladimir Davydov > >> Cc: Christoph Lameter > >> Cc: Pekka Enberg > >> Cc: Michal Hocko > >> Cc: Johannes Weiner > >> Signed-off-by: Andrew Morton > >> --- > >> > >> mm/slub.c | 11 +++++++---- > >> 1 file changed, 7 insertions(+), 4 deletions(-) > >> > >> diff -puN mm/slub.c~slub-fix-memcg_propagate_slab_attrs mm/slub.c > >> --- a/mm/slub.c~slub-fix-memcg_propagate_slab_attrs > >> +++ a/mm/slub.c > >> @@ -5071,15 +5071,18 @@ static void memcg_propagate_slab_attrs(s > >> #ifdef CONFIG_MEMCG_KMEM > >> int i; > >> char *buffer = NULL; > >> + struct kmem_cache *root_cache; > >> > >> - if (!is_root_cache(s)) > >> + if (is_root_cache(s)) > >> return; > >> > >> + root_cache = s->memcg_params->root_cache; > >> + > >> /* > >> * This mean this cache had no attribute written. Therefore, no point > >> * in copying default values around > >> */ > >> - if (!s->max_attr_size) > >> + if (!root_cache->max_attr_size) > >> return; > >> > >> for (i = 0; i < ARRAY_SIZE(slab_attrs); i++) { > >> @@ -5101,7 +5104,7 @@ static void memcg_propagate_slab_attrs(s > >> */ > >> if (buffer) > >> buf = buffer; > >> - else if (s->max_attr_size < ARRAY_SIZE(mbuf)) > >> + else if (root_cache->max_attr_size < ARRAY_SIZE(mbuf)) > >> buf = mbuf; > >> else { > >> buffer = (char *) get_zeroed_page(GFP_KERNEL); > >> @@ -5110,7 +5113,7 @@ static void memcg_propagate_slab_attrs(s > >> buf = buffer; > >> } > >> > >> - attr->show(s->memcg_params->root_cache, buf); > >> + attr->show(root_cache, buf); > >> attr->store(s, buf, strlen(buf)); > >> } > >> > >> _ > >> > >> Patches currently in -mm which might be from vdavydov@parallels.com are > >> > >> slub-fix-memcg_propagate_slab_attrs.patch > >> slb-charge-slabs-to-kmemcg-explicitly.patch > >> mm-get-rid-of-__gfp_kmemcg.patch > >> mm-get-rid-of-__gfp_kmemcg-fix.patch > >> slab-document-kmalloc_order.patch > >> > > > > -- > 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 -- Michal Hocko SUSE Labs -- 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