From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A142CC433E0 for ; Fri, 8 Jan 2021 17:37:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BF6723A53 for ; Fri, 8 Jan 2021 17:37:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728367AbhAHRhl (ORCPT ); Fri, 8 Jan 2021 12:37:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:52954 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728341AbhAHRhl (ORCPT ); Fri, 8 Jan 2021 12:37:41 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 67D83238EC; Fri, 8 Jan 2021 17:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610127419; bh=ueyz6cRCVzjzNZVnZhLuxhfXP2n1emdZjJFhG+I9Lt8=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=pJjxJKIlR47/u+AhzjdIWsop5+Ssjxclcjx8CZfBSo6kZSotudIm9EOdzI5NUrQj/ KDCDCJDBGNwV6wHpRJ25vJpdcOZdcoX2BiWKFOukAcUrHV+h+NrtGF+b5mKm3O0XIE qGwX8z1Za2ugEjDm/rfTFQYX4x2Nc9EsePvtLItwK4D6FM5gzuP3Z+/ShywROK0d6I KvKWXngglhiyti1aY3BwwlYtHVyX3Qk4MGNsjHvU2pH5NiLkyKA7rfCOfRrMpQ2SMg MGwCUqTkhaznPdd7PBSCT5cFQDEiNVyngq0M1wvlUnYaos6SL3l7CDLhEG95TTD95M BqKkUXmjUslig== Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 29DC9352263D; Fri, 8 Jan 2021 09:36:59 -0800 (PST) Date: Fri, 8 Jan 2021 09:36:59 -0800 From: "Paul E. McKenney" To: Vlastimil Babka Cc: Andrew Morton , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-mm@kvack.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, ming.lei@redhat.com, axboe@kernel.dk, kernel-team@fb.com Subject: Re: [PATCH v4 sl-b 0/6] Export return addresses etc. for better diagnostics Message-ID: <20210108173659.GT2743@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20210106011603.GA13180@paulmck-ThinkPad-P72> <20210106134843.ed8e298da92d4fe93b6aa259@linux-foundation.org> <20210106234212.GA20560@paulmck-ThinkPad-P72> <20210108002657.GA21084@paulmck-ThinkPad-P72> <3673d778-163d-15e5-5774-1651926991f6@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3673d778-163d-15e5-5774-1651926991f6@suse.cz> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On Fri, Jan 08, 2021 at 04:35:57PM +0100, Vlastimil Babka wrote: > On 1/8/21 1:26 AM, Paul E. McKenney wrote: > > On Wed, Jan 06, 2021 at 03:42:12PM -0800, Paul E. McKenney wrote: > >> On Wed, Jan 06, 2021 at 01:48:43PM -0800, Andrew Morton wrote: > >> > On Tue, 5 Jan 2021 17:16:03 -0800 "Paul E. McKenney" wrote: > >> > > >> > > This is v4 of the series the improves diagnostics by providing access > >> > > to additional information including the return addresses, slab names, > >> > > offsets, and sizes collected by the sl*b allocators and by vmalloc(). > >> > > >> > Looks reasonable. And not as bloaty as I feared, but it does add ~300 > >> > bytes to my allnoconfig build. Is the CONFIG_ coverage as tight as it > >> > could be? > >> > >> Glad I managed to exceed your expectations. ;-) > >> > >> Let's see... When I do an allnoconfig build, it has CONFIG_PRINTK=n. > >> Given that this facility is based on printk(), I could create an > >> additional patch that #ifdef'ed everything out in CONFIG_PRINTK=n kernels. > >> This would uglify things a bit, but it would save ~300 bytes. > >> > >> If I don't hear otherwise from you, I will put something together, > >> test it, and send it along. > > > > And is a first draft, very lightly tested. Thoughts? > > Looks ok, but I'm not sure it's worth the trouble, there's probably tons of > other code that could be treated like this and nobody is doing that > systematically (at least I haven't heard about kernel tinyfication effort for > years)... Up to Andrew I guess. I am good either way. ;-) Thanx, Paul > Thanks, > Vlastimil > > > Thanx, Paul > > > > ------------------------------------------------------------------------ > > > > commit 4164efdca255093a423b55f44bd788b46d9c648f > > Author: Paul E. McKenney > > Date: Thu Jan 7 13:46:11 2021 -0800 > > > > mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernels > > > > The mem_dump_obj() functionality adds a few hundred bytes, which is a > > small price to pay. Except on kernels built with CONFIG_PRINTK=n, in > > which mem_dump_obj() messages will be suppressed. This commit therefore > > makes mem_dump_obj() be a static inline empty function on kernels built > > with CONFIG_PRINTK=n and excludes all of its support functions as well. > > This avoids kernel bloat on systems that cannot use mem_dump_obj(). > > > > Cc: Christoph Lameter > > Cc: Pekka Enberg > > Cc: David Rientjes > > Cc: Joonsoo Kim > > Cc: > > Suggested-by: Andrew Morton > > Signed-off-by: Paul E. McKenney > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index af7d050..ed75a3a 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -3169,7 +3169,11 @@ unsigned long wp_shared_mapping_range(struct address_space *mapping, > > > > extern int sysctl_nr_trim_pages; > > > > +#ifdef CONFIG_PRINTK > > void mem_dump_obj(void *object); > > +#else > > +static inline void mem_dump_obj(void *object) {} > > +#endif > > > > #endif /* __KERNEL__ */ > > #endif /* _LINUX_MM_H */ > > diff --git a/include/linux/slab.h b/include/linux/slab.h > > index 7ae6040..0c97d78 100644 > > --- a/include/linux/slab.h > > +++ b/include/linux/slab.h > > @@ -186,8 +186,10 @@ void kfree(const void *); > > void kfree_sensitive(const void *); > > size_t __ksize(const void *); > > size_t ksize(const void *); > > +#ifdef CONFIG_PRINTK > > bool kmem_valid_obj(void *object); > > void kmem_dump_obj(void *object); > > +#endif > > > > #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR > > void __check_heap_object(const void *ptr, unsigned long n, struct page *page, > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > > index c18f475..3c8a765 100644 > > --- a/include/linux/vmalloc.h > > +++ b/include/linux/vmalloc.h > > @@ -246,7 +246,7 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) > > int register_vmap_purge_notifier(struct notifier_block *nb); > > int unregister_vmap_purge_notifier(struct notifier_block *nb); > > > > -#ifdef CONFIG_MMU > > +#if defined(CONFIG_MMU) && defined(CONFIG_PRINTK) > > bool vmalloc_dump_obj(void *object); > > #else > > static inline bool vmalloc_dump_obj(void *object) { return false; } > > diff --git a/mm/slab.c b/mm/slab.c > > index dcc55e7..965d277 100644 > > --- a/mm/slab.c > > +++ b/mm/slab.c > > @@ -3635,6 +3635,7 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t flags, > > EXPORT_SYMBOL(__kmalloc_node_track_caller); > > #endif /* CONFIG_NUMA */ > > > > +#ifdef CONFIG_PRINTK > > void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > > { > > struct kmem_cache *cachep; > > @@ -3654,6 +3655,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > > if (DEBUG && cachep->flags & SLAB_STORE_USER) > > kpp->kp_ret = *dbg_userword(cachep, objp); > > } > > +#endif > > > > /** > > * __do_kmalloc - allocate memory > > diff --git a/mm/slab.h b/mm/slab.h > > index ecad9b5..d2e39ab 100644 > > --- a/mm/slab.h > > +++ b/mm/slab.h > > @@ -615,6 +615,7 @@ static inline bool slab_want_init_on_free(struct kmem_cache *c) > > return false; > > } > > > > +#ifdef CONFIG_PRINTK > > #define KS_ADDRS_COUNT 16 > > struct kmem_obj_info { > > void *kp_ptr; > > @@ -626,5 +627,6 @@ struct kmem_obj_info { > > void *kp_stack[KS_ADDRS_COUNT]; > > }; > > void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page); > > +#endif > > > > #endif /* MM_SLAB_H */ > > diff --git a/mm/slab_common.c b/mm/slab_common.c > > index b594413..20b2cc6 100644 > > --- a/mm/slab_common.c > > +++ b/mm/slab_common.c > > @@ -537,6 +537,7 @@ bool slab_is_available(void) > > return slab_state >= UP; > > } > > > > +#ifdef CONFIG_PRINTK > > /** > > * kmem_valid_obj - does the pointer reference a valid slab object? > > * @object: pointer to query. > > @@ -610,6 +611,7 @@ void kmem_dump_obj(void *object) > > pr_info(" %pS\n", kp.kp_stack[i]); > > } > > } > > +#endif > > > > #ifndef CONFIG_SLOB > > /* Create a cache during boot when no slab services are available yet */ > > diff --git a/mm/slob.c b/mm/slob.c > > index ef87ada..8726931 100644 > > --- a/mm/slob.c > > +++ b/mm/slob.c > > @@ -461,11 +461,13 @@ static void slob_free(void *block, int size) > > spin_unlock_irqrestore(&slob_lock, flags); > > } > > > > +#ifdef CONFIG_PRINTK > > void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > > { > > kpp->kp_ptr = object; > > kpp->kp_page = page; > > } > > +#endif > > > > /* > > * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend. > > diff --git a/mm/slub.c b/mm/slub.c > > index 3c1a843..9e205e4 100644 > > --- a/mm/slub.c > > +++ b/mm/slub.c > > @@ -3919,6 +3919,7 @@ int __kmem_cache_shutdown(struct kmem_cache *s) > > return 0; > > } > > > > +#ifdef CONFIG_PRINTK > > void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > > { > > void *base; > > @@ -3958,6 +3959,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > > #endif > > #endif > > } > > +#endif > > > > /******************************************************************** > > * Kmalloc subsystem > > diff --git a/mm/util.c b/mm/util.c > > index 5487022..2d497fe 100644 > > --- a/mm/util.c > > +++ b/mm/util.c > > @@ -983,6 +983,7 @@ int __weak memcmp_pages(struct page *page1, struct page *page2) > > return ret; > > } > > > > +#ifdef CONFIG_PRINTK > > /** > > * mem_dump_obj - Print available provenance information > > * @object: object for which to find provenance information. > > @@ -1013,3 +1014,4 @@ void mem_dump_obj(void *object) > > } > > pr_cont(" non-slab/vmalloc memory.\n"); > > } > > +#endif > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index e3229ff..5002fd6 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -3448,6 +3448,7 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) > > } > > #endif /* CONFIG_SMP */ > > > > +#ifdef CONFIG_PRINTK > > bool vmalloc_dump_obj(void *object) > > { > > struct vm_struct *vm; > > @@ -3460,6 +3461,7 @@ bool vmalloc_dump_obj(void *object) > > vm->nr_pages, (unsigned long)vm->addr, vm->caller); > > return true; > > } > > +#endif > > > > #ifdef CONFIG_PROC_FS > > static void *s_start(struct seq_file *m, loff_t *pos) > > >