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 C4851C77B7E for ; Tue, 30 May 2023 03:07:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229997AbjE3DHs (ORCPT ); Mon, 29 May 2023 23:07:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229672AbjE3DHr (ORCPT ); Mon, 29 May 2023 23:07:47 -0400 Received: from out-27.mta1.migadu.com (out-27.mta1.migadu.com [IPv6:2001:41d0:203:375::1b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD58DB0 for ; Mon, 29 May 2023 20:07:45 -0700 (PDT) Message-ID: <26da75a6-115f-a17a-73bb-381a6b4a3a75@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1685416060; h=from:from:reply-to:subject:subject: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=hhVCqVUhvZRjlBrxLBQaFs82AfnvT+az3ouF0P0dHAo=; b=mlTKSDp327yaErwS5wPyUOFLhylZtOXgmCsi5D/Ahv65c8fdvz5AEvKl8wwzngX+XQyxB7 3xb9bQMv30BmVUREfvhaXsc5w+Js7ZPspdMxeFle/O48tfkrlr7T8waiZphxSHAtfQN4C0 /8vG5h5z2wHuFeuJA+FakXDh+Wquthg= Date: Tue, 30 May 2023 11:07:29 +0800 MIME-Version: 1.0 Subject: Re: [linus:master] [mm] f95bdb700b: stress-ng.ramfs.ops_per_sec -88.8% regression Content-Language: en-US To: paulmck@kernel.org, Kirill Tkhai Cc: RCU , Yujie Liu , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, Andrew Morton , Vlastimil Babka , Roman Gushchin , =?UTF-8?Q?Christian_K=c3=b6nig?= , David Hildenbrand , Davidlohr Bueso , Johannes Weiner , Michal Hocko , Muchun Song , Shakeel Butt , Yang Shi , linux-mm@kvack.org, ying.huang@intel.com, feng.tang@intel.com, fengwei.yin@intel.com References: <202305230837.db2c233f-yujie.liu@intel.com> <896bbb09-d400-ec73-ba3a-b64c6e9bbe46@linux.dev> <44407892-b7bc-4d6c-8e4a-6452f0ee88b9@paulmck-laptop> <095806f1-f7f0-4914-b04b-c874fb25bb83@paulmck-laptop> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: <095806f1-f7f0-4914-b04b-c874fb25bb83@paulmck-laptop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Hi, On 2023/5/29 20:51, Paul E. McKenney wrote: > On Mon, May 29, 2023 at 10:39:21AM +0800, Qi Zheng wrote: [...] >> >> Thanks for such a detailed explanation. >> >> Now I think we can continue to try to complete the idea[1] from >> Kirill Tkhai. The patch moves heavy synchronize_srcu() to delayed >> work, so it doesn't affect on user-visible unregistration speed. >> >> [1]. https://lore.kernel.org/lkml/153365636747.19074.12610817307548583381.stgit@localhost.localdomain/ > > A blast from the past! ;-) > > But yes, moving the long-latency synchronize_srcu() off the user-visible > critical code path can be even better. Yeah, I applied these patches ([PATCH RFC 04/10]~[PATCH RFC 10/10], with few conflicts), the ops/s does get back to the previous levels. I'll continue updating this patchset after doing more testing. Thanks, Qi > > Thanx, Paul