From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f181.google.com (mail-ig0-f181.google.com [209.85.213.181]) by kanga.kvack.org (Postfix) with ESMTP id 8235A6B0255 for ; Mon, 9 Nov 2015 11:39:17 -0500 (EST) Received: by igbhv6 with SMTP id hv6so79038637igb.0 for ; Mon, 09 Nov 2015 08:39:17 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id x23si3995865ioi.94.2015.11.09.08.39.15 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 09 Nov 2015 08:39:15 -0800 (PST) Date: Mon, 9 Nov 2015 17:39:10 +0100 From: Jesper Dangaard Brouer Subject: Re: [PATCH V2 2/2] slub: add missing kmem cgroup support to kmem_cache_free_bulk Message-ID: <20151109173910.7a3c3a18@redhat.com> In-Reply-To: <20151107202548.GO29259@esperanza> References: <20151105153704.1115.10475.stgit@firesoul> <20151105153756.1115.41409.stgit@firesoul> <20151105162514.GI29259@esperanza> <20151107175338.12a0368b@redhat.com> <20151107202548.GO29259@esperanza> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vladimir Davydov Cc: linux-mm@kvack.org, Joonsoo Kim , Andrew Morton , Christoph Lameter , brouer@redhat.com On Sat, 7 Nov 2015 23:25:48 +0300 Vladimir Davydov wrote: > On Sat, Nov 07, 2015 at 05:53:38PM +0100, Jesper Dangaard Brouer wrote: > > On Thu, 5 Nov 2015 19:25:14 +0300 Vladimir Davydov wrote: > > > > > On Thu, Nov 05, 2015 at 04:38:06PM +0100, Jesper Dangaard Brouer wrote: > > > > Initial implementation missed support for kmem cgroup support > > > > in kmem_cache_free_bulk() call, add this. > > > > > > > > If CONFIG_MEMCG_KMEM is not enabled, the compiler should > > > > be smart enough to not add any asm code. > > > > > > > > Signed-off-by: Jesper Dangaard Brouer > > > > > > > > --- > > > > V2: Fixes according to input from: > > > > Vladimir Davydov > > > > and Joonsoo Kim > > > > [...] > > > > diff --git a/mm/slub.c b/mm/slub.c > > > > index 8e9e9b2ee6f3..bc64514ad1bb 100644 > > > > --- a/mm/slub.c > > > > +++ b/mm/slub.c > > > > @@ -2890,6 +2890,9 @@ void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p) > > > > do { > > > > struct detached_freelist df; > > > > > > > > + /* Support for memcg */ > > > > + s = cache_from_obj(s, p[size - 1]); > > > > + [...] > > Yeah, after inspecting build_detached_freelist more closely, I see your > patch is correct. Actually, my patch is not correct... after spending most of my day debugging V3 of patch 1/2, I've just realized this patch it the culprit. We cannot overwrite the original "s", as the second time around the loop, "s" will be a memcg slab cache. And then slab_equal_or_root() cannot find the "root_cache" (s->memcg_params.root_cache). -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer -- 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