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=-17.5 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=ham 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 04552C4361B for ; Wed, 9 Dec 2020 23:23:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9440023B97 for ; Wed, 9 Dec 2020 23:23:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9440023B97 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2B11C6B005C; Wed, 9 Dec 2020 18:23:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 286B56B0068; Wed, 9 Dec 2020 18:23:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 19FAB6B006C; Wed, 9 Dec 2020 18:23:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0115.hostedemail.com [216.40.44.115]) by kanga.kvack.org (Postfix) with ESMTP id 04E516B005C for ; Wed, 9 Dec 2020 18:23:12 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C4E34362B for ; Wed, 9 Dec 2020 23:23:11 +0000 (UTC) X-FDA: 77575321782.15.blow19_1804907273f3 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id A2B1E1814B0C1 for ; Wed, 9 Dec 2020 23:23:11 +0000 (UTC) X-HE-Tag: blow19_1804907273f3 X-Filterd-Recvd-Size: 5035 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Wed, 9 Dec 2020 23:23:11 +0000 (UTC) Date: Wed, 9 Dec 2020 15:23:10 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607556190; bh=FNkanjJRiKGUHvoOf8PjH4Glcl/rM8Sr+vJWnZnM2Fg=; h=From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=kC4FMincGXAIuGjcw2vg52OYrjhASaFkyzOXsRBrhaJdTJT66PVkMuv2nu2Yp8ly1 Q9YR+F5unST9t6G3aED6/FvHgh0Kmel47VDVjb2nczzFdtmXyR8P+DutyqNUuBThbc Hnkx9jnkwLCGh6qsqD4HGxBShJzfHoSdjqY/v/q7TrAtkxwG15emUkUxm+vGZkgC28 tvv2C0esuULdSJw/RgJ/M/j0SeqD6PPZ/qEirWuncC+c1QjW0kStX3yQzRpH/yEXY1 9/kyRHeux2lmkFLAQ19PROIKgRDJY/CuGsr4ukiEzU/Hg9r6xRyq7T7pwpMo04Tkuk y7ChaDCe7CeqA== From: "Paul E. McKenney" To: Vlastimil Babka Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, iamjoonsoo.kim@lge.com, andrii@kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v2 sl-b 3/5] mm: Make mem_dump_obj() handle vmalloc() memory Message-ID: <20201209232310.GI2657@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20201209011124.GA31164@paulmck-ThinkPad-P72> <20201209011303.32737-3-paulmck@kernel.org> <1c25ca09-ec43-df31-a5ba-476397637a53@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1c25ca09-ec43-df31-a5ba-476397637a53@suse.cz> User-Agent: Mutt/1.9.4 (2018-02-28) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Dec 09, 2020 at 06:51:20PM +0100, Vlastimil Babka wrote: > On 12/9/20 2:13 AM, paulmck@kernel.org wrote: > > From: "Paul E. McKenney" > > > > This commit adds vmalloc() support to mem_dump_obj(). Note that the > > vmalloc_dump_obj() function combines the checking and dumping, in > > contrast with the split between kmem_valid_obj() and kmem_dump_obj(). > > The reason for the difference is that the checking in the vmalloc() > > case involves acquiring a global lock, and redundant acquisitions of > > global locks should be avoided, even on not-so-fast paths. > > > > Note that this change causes on-stack variables to be reported as > > vmalloc() storage from kernel_clone() or similar, depending on the degree > > of inlining that your compiler does. This is likely more helpful than > > the earlier "non-paged (local) memory". > > > > Cc: Andrew Morton > > Cc: Joonsoo Kim > > Cc: > > Reported-by: Andrii Nakryiko > > Signed-off-by: Paul E. McKenney > > ... > > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -3431,6 +3431,18 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) > > } > > #endif /* CONFIG_SMP */ > > > > +bool vmalloc_dump_obj(void *object) > > +{ > > + struct vm_struct *vm; > > + void *objp = (void *)PAGE_ALIGN((unsigned long)object); > > + > > + vm = find_vm_area(objp); > > + if (!vm) > > + return false; > > + pr_cont(" vmalloc allocated at %pS\n", vm->caller); > > Would it be useful to print the vm area boundaries too? Like this? I also considered instead using vm->size, but that always seems to include an extra page, so a 4-page span is listed as having 20480 bytes and a one-page span is 8192 bytes. This might be more accurate in some sense, but would be quite confusing to someone trying to compare this size with that requested in the vmalloc() call. Thanx, Paul ------------------------------------------------------------------------ commit 33e0469c289c2f78e5f0d0c463c8ee3357d273c0 Author: Paul E. McKenney Date: Wed Dec 9 15:15:27 2020 -0800 mm: Make mem_obj_dump() vmalloc() dumps include start and length This commit adds the starting address and number of pages to the vmalloc() information dumped by way of vmalloc_dump_obj(). Cc: Andrew Morton Cc: Joonsoo Kim Cc: Reported-by: Andrii Nakryiko Suggested-by: Vlastimil Babka Signed-off-by: Paul E. McKenney diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 7421719..77b1100 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3439,7 +3439,8 @@ bool vmalloc_dump_obj(void *object) vm = find_vm_area(objp); if (!vm) return false; - pr_cont(" vmalloc allocated at %pS\n", vm->caller); + pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n", + vm->nr_pages, (unsigned long)vm->addr, vm->caller); return true; }