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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12C7FECAAA1 for ; Mon, 24 Oct 2022 15:13:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231734AbiJXPNh (ORCPT ); Mon, 24 Oct 2022 11:13:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231181AbiJXPNL (ORCPT ); Mon, 24 Oct 2022 11:13:11 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 449B2B3B32 for ; Mon, 24 Oct 2022 06:50:43 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 696DD2213A; Mon, 24 Oct 2022 13:20:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1666617615; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B+FHugioHev0dYpi/nUm07zjo089onS6uPsLiTaY09U=; b=YGnOEXMUKhpzjhdrRJT8pvM79MmBrBSshmlyuJKl/08O7MznBpOau7zosGEjdO+vIHsT0E wLGXjCQ9To9FKexFzWwLSKyxFCIBfoiLQEBLNlR8xOYqd9ib/rPQalQf7/F0LCodVDG9Rm sqmJTZDfqfRTGxgysN4cOt9sSjEk7QU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1666617615; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B+FHugioHev0dYpi/nUm07zjo089onS6uPsLiTaY09U=; b=rw+pgQMRRv0TsxWnEMcZZfUQ6CMSi6Axy52rV72+fYbmugAPGJzeDj6k/+yUDc5ahHKlJu 7tZD6AZqaiVAVoBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 412D713357; Mon, 24 Oct 2022 13:20:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ykBLDw+RVmMQeAAAMHmgww (envelope-from ); Mon, 24 Oct 2022 13:20:15 +0000 Message-ID: Date: Mon, 24 Oct 2022 15:20:14 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.3 Subject: Re: [PATCH v3] mm/slab: Annotate kmem_cache_node->list_lock as raw Content-Language: en-US To: Jiri Kosina , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: From: Vlastimil Babka In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/21/22 21:18, Jiri Kosina wrote: > From: Jiri Kosina > > The list_lock can be taken in hardirq context when do_drain() is being > called via IPI on all cores, and therefore lockdep complains about it, > because it can't be preempted on PREEMPT_RT. > > That's not a real issue, as SLAB can't be built on PREEMPT_RT anyway, but > we still want to get rid of the warning on non-PREEMPT_RT builds. > > Annotate it therefore as a raw lock in order to get rid of he lockdep > warning below. > > ============================= > [ BUG: Invalid wait context ] > 6.1.0-rc1-00134-ge35184f32151 #4 Not tainted > ----------------------------- > swapper/3/0 is trying to lock: > ffff8bc88086dc18 (&parent->list_lock){..-.}-{3:3}, at: do_drain+0x57/0xb0 > other info that might help us debug this: > context-{2:2} > no locks held by swapper/3/0. > stack backtrace: > CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.1.0-rc1-00134-ge35184f32151 #4 > Hardware name: LENOVO 20K5S22R00/20K5S22R00, BIOS R0IET38W (1.16 ) 05/31/2017 > Call Trace: > > dump_stack_lvl+0x6b/0x9d > __lock_acquire+0x1519/0x1730 > ? build_sched_domains+0x4bd/0x1590 > ? __lock_acquire+0xad2/0x1730 > lock_acquire+0x294/0x340 > ? do_drain+0x57/0xb0 > ? sched_clock_tick+0x41/0x60 > _raw_spin_lock+0x2c/0x40 > ? do_drain+0x57/0xb0 > do_drain+0x57/0xb0 > __flush_smp_call_function_queue+0x138/0x220 > __sysvec_call_function+0x4f/0x210 > sysvec_call_function+0x4b/0x90 > > > asm_sysvec_call_function+0x16/0x20 > RIP: 0010:mwait_idle+0x5e/0x80 > Code: 31 d2 65 48 8b 04 25 80 ed 01 00 48 89 d1 0f 01 c8 48 8b 00 a8 08 75 14 66 90 0f 00 2d 0b 78 46 00 31 c0 48 89 c1 fb 0f 01 c9 06 fb 0f 1f 44 00 00 65 48 8b 04 25 80 ed 01 00 f0 80 60 02 df > RSP: 0000:ffffa90940217ee0 EFLAGS: 00000246 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9bb9f93a > RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000001 > R10: ffffa90940217ea8 R11: 0000000000000000 R12: ffffffffffffffff > R13: 0000000000000000 R14: ffff8bc88127c500 R15: 0000000000000000 > ? default_idle_call+0x1a/0xa0 > default_idle_call+0x4b/0xa0 > do_idle+0x1f1/0x2c0 > ? _raw_spin_unlock_irqrestore+0x56/0x70 > cpu_startup_entry+0x19/0x20 > start_secondary+0x122/0x150 > secondary_startup_64_no_verify+0xce/0xdb > > > Signed-off-by: Jiri Kosina Thanks, added to slab/for-6.2/locking ... > diff --git a/mm/slab.h b/mm/slab.h > index 0202a8c2f0d2..7a705e4228c8 100644 > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -750,7 +750,11 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, > * The slab lists for all objects. > */ > struct kmem_cache_node { > +#ifdef CONFIG_SLAB > + raw_spinlock_t list_lock; > +#else > spinlock_t list_lock; > +#endif > > #ifdef CONFIG_SLAB > struct list_head slabs_partial; /* partial list first, better asm code */ Simplified a bit. Since we already have CONFIG_SLAB/CONFIG_SLUB #ifdef sections, moved the list_lock there.