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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 57848C433E9 for ; Thu, 3 Sep 2020 17:48:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 154872072A for ; Thu, 3 Sep 2020 17:48:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 154872072A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=bitdefender.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C3C868E0001; Thu, 3 Sep 2020 13:48:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 93AA76B006C; Thu, 3 Sep 2020 13:48:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 768A48E0001; Thu, 3 Sep 2020 13:48:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 0BA956B0068 for ; Thu, 3 Sep 2020 13:48:12 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id B9170180AD817 for ; Thu, 3 Sep 2020 17:48:11 +0000 (UTC) X-FDA: 77222483982.09.wall43_5e14064270ab Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 82F08180AD806 for ; Thu, 3 Sep 2020 17:48:11 +0000 (UTC) X-HE-Tag: wall43_5e14064270ab X-Filterd-Recvd-Size: 5474 Received: from mx01.bbu.dsd.mx.bitdefender.com (mx01.bbu.dsd.mx.bitdefender.com [91.199.104.161]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Sep 2020 17:48:10 +0000 (UTC) Received: from smtp.bitdefender.com (smtp01.buh.bitdefender.com [10.17.80.75]) by mx01.bbu.dsd.mx.bitdefender.com (Postfix) with ESMTPS id 60F3630747C8; Thu, 3 Sep 2020 20:48:09 +0300 (EEST) Received: from localhost.localdomain (unknown [195.189.155.252]) by smtp.bitdefender.com (Postfix) with ESMTPSA id 3BC8C3072788; Thu, 3 Sep 2020 20:48:09 +0300 (EEST) From: =?UTF-8?q?Adalbert=20Laz=C4=83r?= To: linux-mm@kvack.org Cc: Andrew Morton , Alexander Graf , Stefan Hajnoczi , Jerome Glisse , Paolo Bonzini , Mircea Cirjaliu , =?UTF-8?q?Adalbert=20Laz=C4=83r?= Subject: [RFC PATCH 3/5] mm/mmu_notifier: remove lockdep map, allow mmu notifier to be used in nested scenarios Date: Thu, 3 Sep 2020 20:47:28 +0300 Message-Id: <20200903174730.2685-4-alazar@bitdefender.com> In-Reply-To: <20200903174730.2685-1-alazar@bitdefender.com> References: <20200903174730.2685-1-alazar@bitdefender.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Rspamd-Queue-Id: 82F08180AD806 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 Content-Transfer-Encoding: quoted-printable 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: From: Mircea Cirjaliu The combination of remote mapping + KVM causes nested range invalidations= , which reports lockdep warnings. Signed-off-by: Mircea Cirjaliu Signed-off-by: Adalbert Laz=C4=83r --- include/linux/mmu_notifier.h | 5 +---- mm/mmu_notifier.c | 19 ------------------- 2 files changed, 1 insertion(+), 23 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 736f6918335e..81ea457d41be 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -440,12 +440,10 @@ mmu_notifier_invalidate_range_start(struct mmu_noti= fier_range *range) { might_sleep(); =20 - lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); if (mm_has_notifiers(range->mm)) { range->flags |=3D MMU_NOTIFIER_RANGE_BLOCKABLE; __mmu_notifier_invalidate_range_start(range); } - lock_map_release(&__mmu_notifier_invalidate_range_start_map); } =20 static inline int @@ -453,12 +451,11 @@ mmu_notifier_invalidate_range_start_nonblock(struct= mmu_notifier_range *range) { int ret =3D 0; =20 - lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); if (mm_has_notifiers(range->mm)) { range->flags &=3D ~MMU_NOTIFIER_RANGE_BLOCKABLE; ret =3D __mmu_notifier_invalidate_range_start(range); } - lock_map_release(&__mmu_notifier_invalidate_range_start_map); + return ret; } =20 diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 06852b896fa6..928751bd8630 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -22,12 +22,6 @@ /* global SRCU for all MMs */ DEFINE_STATIC_SRCU(srcu); =20 -#ifdef CONFIG_LOCKDEP -struct lockdep_map __mmu_notifier_invalidate_range_start_map =3D { - .name =3D "mmu_notifier_invalidate_range_start" -}; -#endif - /* * The mmu_notifier_subscriptions structure is allocated and installed i= n * mm->notifier_subscriptions inside the mm_take_all_locks() protected @@ -242,8 +236,6 @@ mmu_interval_read_begin(struct mmu_interval_notifier = *interval_sub) * will always clear the below sleep in some reasonable time as * subscriptions->invalidate_seq is even in the idle state. */ - lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); - lock_map_release(&__mmu_notifier_invalidate_range_start_map); if (is_invalidating) wait_event(subscriptions->wq, READ_ONCE(subscriptions->invalidate_seq) !=3D seq); @@ -572,13 +564,11 @@ void __mmu_notifier_invalidate_range_end(struct mmu= _notifier_range *range, struct mmu_notifier_subscriptions *subscriptions =3D range->mm->notifier_subscriptions; =20 - lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); if (subscriptions->has_itree) mn_itree_inv_end(subscriptions); =20 if (!hlist_empty(&subscriptions->list)) mn_hlist_invalidate_end(subscriptions, range, only_end); - lock_map_release(&__mmu_notifier_invalidate_range_start_map); } =20 void __mmu_notifier_invalidate_range(struct mm_struct *mm, @@ -612,13 +602,6 @@ int __mmu_notifier_register(struct mmu_notifier *sub= scription, lockdep_assert_held_write(&mm->mmap_sem); BUG_ON(atomic_read(&mm->mm_users) <=3D 0); =20 - if (IS_ENABLED(CONFIG_LOCKDEP)) { - fs_reclaim_acquire(GFP_KERNEL); - lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); - lock_map_release(&__mmu_notifier_invalidate_range_start_map); - fs_reclaim_release(GFP_KERNEL); - } - if (!mm->notifier_subscriptions) { /* * kmalloc cannot be called under mm_take_all_locks(), but we @@ -1062,8 +1045,6 @@ void mmu_interval_notifier_remove(struct mmu_interv= al_notifier *interval_sub) * The possible sleep on progress in the invalidation requires the * caller not hold any locks held by invalidation callbacks. */ - lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); - lock_map_release(&__mmu_notifier_invalidate_range_start_map); if (seq) wait_event(subscriptions->wq, READ_ONCE(subscriptions->invalidate_seq) !=3D seq);