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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 539FEC10DC1 for ; Thu, 30 Nov 2023 12:21:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C5F228D004B; Thu, 30 Nov 2023 07:21:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C0F0D8D0001; Thu, 30 Nov 2023 07:21:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AFF2C8D004B; Thu, 30 Nov 2023 07:21:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id A111B8D0001 for ; Thu, 30 Nov 2023 07:21:10 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 77E551C010B for ; 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charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 6162780018 X-Stat-Signature: cew3wrzudiqaw68ket1khp41htmnt6ce X-HE-Tag: 1701346868-139751 X-HE-Meta: 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 7OYZf9RD ktmqzontmZTAQeoBOPNYASiKNBmtsYAF49iq+wBhXMrnVllwgpjfs4S2wLpzSGAtOiNznV7gjGJXVIp9PpQqFuoMKnY7sGP9g9QK0bOxHudacjHIAJcSlveNEUcbEw4E8kw3W2YT6vloeAkuHk0+DAWXODeh5CQ/24vKsHeF+FTl8Uy5Rc7i8XNrUo+UdwCrm8gS22JjE9ryiuDj5QPuo/k7gzP31is8vA6/fTRLeEwE4lFv2BBNyx0njxqEF4lgVh4ZSSxpoaKzJiFNcDilDj5H60JNoTJSwVKoJDp68VGYg06f23wsXH90ckgeQjsUNCpzDo2lNs1aB6cRDpLOL8+F2oX6Mg1cdgys7jryqEf6vCtE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Nov 29, 2023 at 05:57:11PM -0500, Waiman Long wrote: > On 11/28/23 11:04, Catalin Marinas wrote: > > The problem is looking up the object tree for each per-cpu offset. We > > can make the percpu pointer handling O(1) since freeing is only done by > > the main __percpu pointer, so that's the only one needing a look-up. So > > far the per-cpu pointers are not tracked for leaking, only scanned. > > > > We could just add the per_cpu_ptr(ptr, 0) to the kmemleak > > object_tree_root but when scanning we don't have an inverse function to > > get the __percpu pointer back and calculate the pointers for the other > > CPUs (well, we could with some hacks but they are probably fragile). > > > > What I came up with is a separate object_percpu_tree_root similar to the > > object_phys_tree_root. The only reason for these additional trees is to > > look up the kmemleak metadata when needed (usually freeing). They don't > > contain objects that are tracked for actual leaking, only scanned. A > > briefly tested patch below. I need to go through it again, update some > > comments and write a commit log: [...] > The patch looks reasonable to me. It also has a side effect of reducing the > # of kmemleak objects to track especially for system with large number of > CPUs. Of course, we still need more testing to make sure that it won't break > anything. Thanks for having a look. I'll tidy it up and post today or tomorrow. It can stay in next for a bit before upstreaming to get some exposure (though not sure many test -next with kmemleak enabled). -- Catalin