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 57DA3C00A5A for ; Thu, 19 Jan 2023 04:01:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BFCC36B0073; Wed, 18 Jan 2023 23:01:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B85CE6B0074; Wed, 18 Jan 2023 23:01:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9FFBC6B0075; Wed, 18 Jan 2023 23:01:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 883756B0073 for ; Wed, 18 Jan 2023 23:01:27 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 4A70C1C1D5F for ; Thu, 19 Jan 2023 04:01:27 +0000 (UTC) X-FDA: 80370199014.27.1166E50 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf27.hostedemail.com (Postfix) with ESMTP id BFE3B4001B for ; Thu, 19 Jan 2023 04:01:25 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=dQVaQqWM; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf27.hostedemail.com: domain of longman@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=longman@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674100885; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=YFRn2G3kICVUTv0CVX/GON7X4LfKNre2jK8Ma2QSF+o=; b=5kLN4ifPHDALvLZs6Wy1SHDCBF5WL33CpmaEBqHLs/G5yQmlp2IxnW3PYLvKYQ44p6uCys AYwOxwMgR1VfmhVC0BUVrk6AN3JF8BkweHmHgdX3OABbqHrtfmnvtYpDnFhWaCw2F87m0h MpPBIRcmFrb8H8sHit+LUIDP7ze+VJ0= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=dQVaQqWM; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf27.hostedemail.com: domain of longman@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=longman@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674100885; a=rsa-sha256; cv=none; b=Zi7dNyhOAakfMjm8RiC6LC0QO7MT1dQmIokphlYQ/SkuwxYZos70TaLwB2p7blIHLhodix NIMQwP0F6JhWhOeCMXQTsTvYpsJEUEwk3tdt/Hr7Wkj/FkQe5i3FjXqkK3u4y64G/sIrW4 BwWmUcfd0CiNv3nO+V9UO3PYERq2GJ8= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674100885; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YFRn2G3kICVUTv0CVX/GON7X4LfKNre2jK8Ma2QSF+o=; b=dQVaQqWMplEk2zVszHKXq+Z4TKjHI8hHMwFslIeF/iCfVWMf3GlFwd+7tZx4336jPFKHzw Cq0fy7iXf/LzWjbds4Ku2WRiK6N0pgOmJBMNEpEV1VPKGx+dRnvoO0hf+rUVhJrq5N094x 35YH/i5fWPYPgE+gq4X11ihLHjubhB8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-584-1DQLsC-QPwm5vFLMtYRjPg-1; Wed, 18 Jan 2023 23:01:21 -0500 X-MC-Unique: 1DQLsC-QPwm5vFLMtYRjPg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0E2E53814950; Thu, 19 Jan 2023 04:01:21 +0000 (UTC) Received: from llong.com (unknown [10.22.8.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id B6CE551E5; Thu, 19 Jan 2023 04:01:20 +0000 (UTC) From: Waiman Long To: Catalin Marinas , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song , Waiman Long Subject: [RESEND PATCH v2 1/2] mm/kmemleak: Simplify kmemleak_cond_resched() usage Date: Wed, 18 Jan 2023 23:01:10 -0500 Message-Id: <20230119040111.350923-2-longman@redhat.com> In-Reply-To: <20230119040111.350923-1-longman@redhat.com> References: <20230119040111.350923-1-longman@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: BFE3B4001B X-Stat-Signature: iw5ad5tfuxtxzw3hu7yuwi1np1fkr599 X-HE-Tag: 1674100885-471987 X-HE-Meta: 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 O4A== 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: The presence of a pinned argument and the 64k loop count make kmemleak_cond_resched() a bit more complex to read. The pinned argument is used only by first kmemleak_scan() loop. Simplify the usage of kmemleak_cond_resched() by removing the pinned argument and always do a get_object()/put_object() sequence. In addition, the 64k loop is removed by using need_resched() to decide if kmemleak_cond_resched() should be called. Signed-off-by: Waiman Long Reviewed-by: Catalin Marinas --- mm/kmemleak.c | 48 ++++++++++++------------------------------------ 1 file changed, 12 insertions(+), 36 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 267332904354..e7cb521236bf 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1463,22 +1463,17 @@ static void scan_gray_list(void) /* * Conditionally call resched() in an object iteration loop while making sure * that the given object won't go away without RCU read lock by performing a - * get_object() if !pinned. - * - * Return: false if can't do a cond_resched() due to get_object() failure - * true otherwise + * get_object() if necessaary. */ -static bool kmemleak_cond_resched(struct kmemleak_object *object, bool pinned) +static void kmemleak_cond_resched(struct kmemleak_object *object) { - if (!pinned && !get_object(object)) - return false; + if (!get_object(object)) + return; /* Try next object */ rcu_read_unlock(); cond_resched(); rcu_read_lock(); - if (!pinned) - put_object(object); - return true; + put_object(object); } /* @@ -1492,15 +1487,12 @@ static void kmemleak_scan(void) struct zone *zone; int __maybe_unused i; int new_leaks = 0; - int loop_cnt = 0; jiffies_last_scan = jiffies; /* prepare the kmemleak_object's */ rcu_read_lock(); list_for_each_entry_rcu(object, &object_list, object_list) { - bool obj_pinned = false; - raw_spin_lock_irq(&object->lock); #ifdef DEBUG /* @@ -1526,19 +1518,13 @@ static void kmemleak_scan(void) /* reset the reference count (whiten the object) */ object->count = 0; - if (color_gray(object) && get_object(object)) { + if (color_gray(object) && get_object(object)) list_add_tail(&object->gray_list, &gray_list); - obj_pinned = true; - } raw_spin_unlock_irq(&object->lock); - /* - * Do a cond_resched() every 64k objects to avoid soft lockup. - */ - if (!(++loop_cnt & 0xffff) && - !kmemleak_cond_resched(object, obj_pinned)) - loop_cnt--; /* Try again on next object */ + if (need_resched()) + kmemleak_cond_resched(object); } rcu_read_unlock(); @@ -1605,14 +1591,9 @@ static void kmemleak_scan(void) * scan and color them gray until the next scan. */ rcu_read_lock(); - loop_cnt = 0; list_for_each_entry_rcu(object, &object_list, object_list) { - /* - * Do a cond_resched() every 64k objects to avoid soft lockup. - */ - if (!(++loop_cnt & 0xffff) && - !kmemleak_cond_resched(object, false)) - loop_cnt--; /* Try again on next object */ + if (need_resched()) + kmemleak_cond_resched(object); /* * This is racy but we can save the overhead of lock/unlock @@ -1647,14 +1628,9 @@ static void kmemleak_scan(void) * Scanning result reporting. */ rcu_read_lock(); - loop_cnt = 0; list_for_each_entry_rcu(object, &object_list, object_list) { - /* - * Do a cond_resched() every 64k objects to avoid soft lockup. - */ - if (!(++loop_cnt & 0xffff) && - !kmemleak_cond_resched(object, false)) - loop_cnt--; /* Try again on next object */ + if (need_resched()) + kmemleak_cond_resched(object); /* * This is racy but we can save the overhead of lock/unlock -- 2.31.1