From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f172.google.com (mail-lb0-f172.google.com [209.85.217.172]) by kanga.kvack.org (Postfix) with ESMTP id B1D6C6B0035 for ; Tue, 22 Apr 2014 06:53:05 -0400 (EDT) Received: by mail-lb0-f172.google.com with SMTP id c11so4151284lbj.31 for ; Tue, 22 Apr 2014 03:53:04 -0700 (PDT) Received: from relay.parallels.com (relay.parallels.com. [195.214.232.42]) by mx.google.com with ESMTPS id on7si26138753lbb.137.2014.04.22.03.53.03 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 Apr 2014 03:53:03 -0700 (PDT) Message-ID: <53564A09.3090008@parallels.com> Date: Tue, 22 Apr 2014 14:52:57 +0400 From: Vladimir Davydov MIME-Version: 1.0 Subject: Re: + slub-fix-memcg_propagate_slab_attrs.patch added to -mm tree References: <53518631.cuNCoAbpOk1NRWDf%akpm@linux-foundation.org> <20140422103051.GH29311@dhcp22.suse.cz> In-Reply-To: <20140422103051.GH29311@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: mm-commits@vger.kernel.org, penberg@kernel.org, hannes@cmpxchg.org, cl@linux.com, linux-mm@kvack.org, Andrew Morton 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. > >> 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