From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id B54B96B0044 for ; Tue, 23 Dec 2008 09:43:23 -0500 (EST) Date: Tue, 23 Dec 2008 15:43:08 +0100 From: Johannes Weiner Subject: Re: [PATCH] failslab for SLUB Message-ID: <20081223144307.GA3215@cmpxchg.org> References: <20081223103616.GA7217@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Pekka J Enberg Cc: Akinobu Mita , linux-kernel@vger.kernel.org, Christoph Lameter , Matt Mackall , linux-mm@kvack.org, akpm@linux-foundation.org List-ID: On Tue, Dec 23, 2008 at 03:00:43PM +0200, Pekka J Enberg wrote: > Hi Akinobu, > > On Tue, 23 Dec 2008, Akinobu Mita wrote: > > Currently fault-injection capability for SLAB allocator is only available > > to SLAB. This patch makes it available to SLUB, too. > > The code duplication in your patch is unfortunate. What do you think of > this patch instead? > > Pekka > > >>From 98bb6a5dade01ab007b3994a1456b7cac6b1f905 Mon Sep 17 00:00:00 2001 > From: Akinobu Mita > Date: Tue, 23 Dec 2008 19:37:01 +0900 > Subject: [PATCH] SLUB: failslab support > > Currently fault-injection capability for SLAB allocator is only > available to SLAB. This patch makes it available to SLUB, too. > > [penberg@cs.helsinki.fi: unify slab and slub implementations] > Cc: Christoph Lameter > Cc: Matt Mackall > Signed-off-by: Akinobu Mita > Signed-off-by: Pekka Enberg > --- > include/linux/fault-inject.h | 9 +++++ > lib/Kconfig.debug | 1 + > mm/Makefile | 1 + > mm/failslab.c | 59 +++++++++++++++++++++++++++++++++ > mm/slab.c | 75 +++--------------------------------------- > mm/slub.c | 4 ++ > 6 files changed, 79 insertions(+), 70 deletions(-) > create mode 100644 mm/failslab.c > [...] > diff --git a/mm/failslab.c b/mm/failslab.c > new file mode 100644 > index 0000000..7c6ea64 > --- /dev/null > +++ b/mm/failslab.c > @@ -0,0 +1,59 @@ > +#include > + > +static struct { > + struct fault_attr attr; > + u32 ignore_gfp_wait; > +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS > + struct dentry *ignore_gfp_wait_file; > +#endif > +} failslab = { > + .attr = FAULT_ATTR_INITIALIZER, > + .ignore_gfp_wait = 1, > +}; > + > +bool should_failslab(size_t size, gfp_t gfpflags) > +{ > + if (gfpflags & __GFP_NOFAIL) > + return false; > + > + if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT)) > + return false; > + > + return should_fail(&failslab.attr, size); > +} > + > +static int __init setup_failslab(char *str) > +{ > + return setup_fault_attr(&failslab.attr, str); > +} > +__setup("failslab=", setup_failslab); > + > +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS > + > +static int __init failslab_debugfs_init(void) > +{ > + mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; > + struct dentry *dir; > + int err; > + > + err = init_fault_attr_dentries(&failslab.attr, "failslab"); > + if (err) > + return err; > + dir = failslab.attr.dentries.dir; > + > + failslab.ignore_gfp_wait_file = > + debugfs_create_bool("ignore-gfp-wait", mode, dir, > + &failslab.ignore_gfp_wait); > + > + if (!failslab.ignore_gfp_wait_file) { > + err = -ENOMEM; > + debugfs_remove(failslab.ignore_gfp_wait_file); > + cleanup_fault_attr_dentries(&failslab.attr); > + } > + > + return err; > +} > + > +late_initcall(failslab_debugfs_init); > + > +#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ > diff --git a/mm/slab.c b/mm/slab.c > index 0918751..c347dd8 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -3106,79 +3106,14 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, > #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) > #endif > > -#ifdef CONFIG_FAILSLAB > - > -static struct failslab_attr { > - > - struct fault_attr attr; > - > - u32 ignore_gfp_wait; > -#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS > - struct dentry *ignore_gfp_wait_file; > -#endif > - > -} failslab = { > - .attr = FAULT_ATTR_INITIALIZER, > - .ignore_gfp_wait = 1, > -}; > - > -static int __init setup_failslab(char *str) > -{ > - return setup_fault_attr(&failslab.attr, str); > -} > -__setup("failslab=", setup_failslab); > - > -static int should_failslab(struct kmem_cache *cachep, gfp_t flags) > +static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) > { > if (cachep == &cache_cache) > - return 0; > - if (flags & __GFP_NOFAIL) > - return 0; > - if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT)) > - return 0; > + return false; > > - return should_fail(&failslab.attr, obj_size(cachep)); > + return should_failslab(obj_size(cachep), flags); > } > > -#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS > - > -static int __init failslab_debugfs(void) > -{ > - mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; > - struct dentry *dir; > - int err; > - > - err = init_fault_attr_dentries(&failslab.attr, "failslab"); > - if (err) > - return err; > - dir = failslab.attr.dentries.dir; > - > - failslab.ignore_gfp_wait_file = > - debugfs_create_bool("ignore-gfp-wait", mode, dir, > - &failslab.ignore_gfp_wait); > - > - if (!failslab.ignore_gfp_wait_file) { > - err = -ENOMEM; > - debugfs_remove(failslab.ignore_gfp_wait_file); > - cleanup_fault_attr_dentries(&failslab.attr); > - } > - > - return err; > -} > - > -late_initcall(failslab_debugfs); > - > -#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ > - > -#else /* CONFIG_FAILSLAB */ > - > -static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags) > -{ > - return 0; > -} > - > -#endif /* CONFIG_FAILSLAB */ > - > static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) > { > void *objp; > @@ -3381,7 +3316,7 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, > unsigned long save_flags; > void *ptr; > > - if (should_failslab(cachep, flags)) > + if (slab_should_failslab(cachep, flags)) should_failslab()? > return NULL; > > cache_alloc_debugcheck_before(cachep, flags); > @@ -3457,7 +3392,7 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) > unsigned long save_flags; > void *objp; > > - if (should_failslab(cachep, flags)) > + if (slab_should_failslab(cachep, flags)) should_failslab()? 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