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 2A07DC76196 for ; Tue, 11 Apr 2023 14:27:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230118AbjDKO1l (ORCPT ); Tue, 11 Apr 2023 10:27:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36202 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230460AbjDKO1a (ORCPT ); Tue, 11 Apr 2023 10:27:30 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6733259C7; Tue, 11 Apr 2023 07:27:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1681223221; x=1712759221; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=D+lwxEBI11azd214/0YlxBDefvmnj9OAR5+LS8svKZY=; b=GojyjcZCUGkSIO0w3goaYVnvvJ9HF10X8Z3RogtqJ47kbW1g7DWs726z SKGEpRXQ7X+N4R+QYFVxJRaUzM92inobsnJupVsTMntgsu49sArI8S8Th 1U7fgax0/eJOgLnTg2abzpGrteiaXpmF/yw6cXJ08QUZ3BiiMkFkC0GpN TW05M9y9SFQjyynQUX049/JI9ODzuno1N8EuKtHqtqHoBaxxTLgNu7jXs wCygWcQWjMgleQViLw01PBk9xW5N4mdP21vcwtht1d5t0sFlVaP+sbLkC 1hb9ToN4MV9Eo1WCTcVOFLHukAe8zaClOZ4kjJE0fHpaf9tgeEEQ99dWQ Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10677"; a="346300492" X-IronPort-AV: E=Sophos;i="5.98,336,1673942400"; d="scan'208";a="346300492" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2023 07:26:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10677"; a="682097229" X-IronPort-AV: E=Sophos;i="5.98,336,1673942400"; d="scan'208";a="682097229" Received: from ubuntu.bj.intel.com ([10.238.155.108]) by orsmga007.jf.intel.com with ESMTP; 11 Apr 2023 07:26:53 -0700 From: Zqiang To: urezki@gmail.com, paulmck@kernel.org, frederic@kernel.org, joel@joelfernandes.org, qiang1.zhang@intel.com Cc: qiang.zhang1211@gmail.com, rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCHi v4] rcu/kvfree: Prevents cache growing when the backoff_page_cache_fill is set Date: Tue, 11 Apr 2023 22:27:33 +0800 Message-Id: <20230411142733.1011223-1-qiang1.zhang@intel.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Currently, in kfree_rcu_shrink_scan(), the drain_page_cache() is executed before kfree_rcu_monitor() to drain page cache, if the bnode structure's->gp_snap has done, the kvfree_rcu_bulk() will fill the page cache again in kfree_rcu_monitor(), this commit add a check for krcp structure's->backoff_page_cache_fill in put_cached_bnode(), if the krcp structure's->backoff_page_cache_fill is set, prevent page cache growing and start fill page from krcp->nr_bkv_objs, if the krcp->nr_bkv_objs is greater or equal to nr_pages, not alloc page, avoid unnecessary __get_free_page() calls. Signed-off-by: Zqiang --- kernel/rcu/tree.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 41daae3239b5..d5639025bd1a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2908,6 +2908,8 @@ static inline bool put_cached_bnode(struct kfree_rcu_cpu *krcp, struct kvfree_rcu_bulk_data *bnode) { + if (atomic_read(&krcp->backoff_page_cache_fill)) + return false; // Check the limit. if (krcp->nr_bkv_objs >= rcu_min_cached_objs) return false; @@ -3223,7 +3225,7 @@ static void fill_page_cache_func(struct work_struct *work) nr_pages = atomic_read(&krcp->backoff_page_cache_fill) ? 1 : rcu_min_cached_objs; - for (i = 0; i < nr_pages; i++) { + for (i = krcp->nr_bkv_objs; i < nr_pages; i++) { bnode = (struct kvfree_rcu_bulk_data *) __get_free_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); -- 2.32.0