From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f172.google.com (mail-qc0-f172.google.com [209.85.216.172]) by kanga.kvack.org (Postfix) with ESMTP id 0D6356B003B for ; Fri, 29 Aug 2014 01:09:23 -0400 (EDT) Received: by mail-qc0-f172.google.com with SMTP id o8so1881622qcw.17 for ; Thu, 28 Aug 2014 22:09:22 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id q64si8880272qga.126.2014.08.28.22.09.22 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 Aug 2014 22:09:22 -0700 (PDT) Date: Fri, 29 Aug 2014 13:09:17 +0800 From: WANG Chao Subject: Re: [PATCH] mm, slub: do not add duplicate sysfs Message-ID: <20140829050917.GB2831@dhcp-17-37.nay.redhat.com> References: <1409152488-21227-1-git-send-email-chaowang@redhat.com> <20140828043211.GD3971@dhcp-17-37.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrew Morton , Pekka Enberg , David Rientjes , Joonsoo Kim , "open list:SLAB ALLOCATOR" , open list On 08/28/14 at 09:47am, Christoph Lameter wrote: > On Thu, 28 Aug 2014, WANG Chao wrote: > > > What about failslab_store()? SLAB_FAILSLAB is also a nomerge flag. > > > Subject: slub: Disable tracing and failslab for merged slabs > > Tracing of mergeable slabs as well as uses of failslab are > confusing since the objects of multiple slab caches will be > affected. Moreover this creates a situation where a mergeable > slab will become unmergeable. > > If tracing or failslab testing is desired then it may be best to > switch merging off for starters. > > Signed-off-by: Christoph Lameter > > Index: linux/mm/slub.c > =================================================================== > --- linux.orig/mm/slub.c 2014-08-08 11:52:30.039681592 -0500 > +++ linux/mm/slub.c 2014-08-28 09:45:58.748840392 -0500 > @@ -4604,6 +4604,14 @@ static ssize_t trace_show(struct kmem_ca > static ssize_t trace_store(struct kmem_cache *s, const char *buf, > size_t length) > { > + /* > + * Tracing a merged cache is going to give confusing results > + * as well as cause other issues like converting a mergeable > + * cache into an umergeable one. > + */ > + if (s->refcount > 1) > + return -EINVAL; > + > s->flags &= ~SLAB_TRACE; > if (buf[0] == '1') { > s->flags &= ~__CMPXCHG_DOUBLE; > @@ -4721,6 +4729,9 @@ static ssize_t failslab_show(struct kmem > static ssize_t failslab_store(struct kmem_cache *s, const char *buf, > size_t length) > { > + if (s->refcount > 1) > + return -EINVAL; > + > s->flags &= ~SLAB_FAILSLAB; > if (buf[0] == '1') > s->flags |= SLAB_FAILSLAB; This works for me. Thanks for the fix. WANG Chao -- 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