From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f45.google.com (mail-lf1-f45.google.com [209.85.167.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CBC01E865; Mon, 15 Jan 2024 10:57:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AgQ8wfML" Received: by mail-lf1-f45.google.com with SMTP id 2adb3069b0e04-50eabd1c701so10387604e87.3; Mon, 15 Jan 2024 02:57:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1705316261; x=1705921061; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=OrIEIVQ0TBrRPvuwtl5pM5zpIBQQMtqiH1n/HgWgNXE=; b=AgQ8wfMLvbxuGAZWuXvayMu/lOt4Mg5apEt2j6FreqLve93gdLRisRtOvmiYWy8SKX xmmrQ7qb4Ix1V4JfubGAm0arcsKh1/RQ0j0vzk7Ez67dTbMRvDnxORo30ehl2VBjTHop vUGj8wDC0lc+7vk3pkul8Stv9VHF1tVDzds+W3uIfBdTyhdWiaSc2DAek/CS2WuSPGRY ys19cy2ceruNm9GTKTN7KQkqAXf0BzuPrjWBSd3N/tdyqHM3KwAJHlvyW4VV/Okt+Xgv giPmVn2F6aHa60tPqU4msw6NXd2l43ICsLfwbfzhe+GWPxZI9pzfSbDQtUW4Pocl0ZBq kjNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705316261; x=1705921061; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=OrIEIVQ0TBrRPvuwtl5pM5zpIBQQMtqiH1n/HgWgNXE=; b=iL8h2yALHDyqJDfcY6MRL1AgGI9w6kPABLZiHMR1aQ+Fa1En0RM+FUBhsOGzlpA+DC cZyY8FQ68XK84sZwwyI5tvezDn2NxKONxer3Cvii6XMV8lp0Gg5FycsvLVJSp2Frl0u3 f7jdVWYAgOnvbuodxWAanMdkLUkh3Ijngc8jMG+bBZKXDXCPOLaPEseCds092tplOMPV tCuk52q+rvx5X6AZRDi/kUBClRZ7dJWTXLEjVwEDxKuyOuogU115CFhD+eTLCyagraY9 psHa/oh4Q/d9sJCmqicCJ9IBLrINlfUHcVvchtgmxEA1URoC/pvX6WuRBnzIglvpM7D4 2d0Q== X-Gm-Message-State: AOJu0Yzowt417OqNU8jhG3I+qAvoF37sOVsTMarKuDmR2IErjOd7dQOw XqapiMQ+ioipa3SBlxkuUto= X-Google-Smtp-Source: AGHT+IEa0v5VEciA8p40cqffWLy5aX9mFUxDYt5fIXN7BFhA3Lpz818bnUfp+4fe2fFbd348aoRTvw== X-Received: by 2002:a05:6512:2247:b0:50e:a15c:6b61 with SMTP id i7-20020a056512224700b0050ea15c6b61mr2696333lfu.116.1705316261487; Mon, 15 Jan 2024 02:57:41 -0800 (PST) Received: from pc636 (host-90-233-221-202.mobileonline.telia.com. [90.233.221.202]) by smtp.gmail.com with ESMTPSA id q12-20020ac24a6c000000b0050e7e304238sm1440881lfp.19.2024.01.15.02.57.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Jan 2024 02:57:41 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Mon, 15 Jan 2024 11:57:39 +0100 To: Z qiang Cc: Z qiang , "Paul E . McKenney" , RCU , Neeraj upadhyay , Boqun Feng , Hillf Danton , Joel Fernandes , LKML , Oleksiy Avramchenko , Frederic Weisbecker Subject: Re: [PATCH v4 4/4] rcu: Support direct wake-up of synchronize_rcu() users Message-ID: References: <20240104162510.72773-1-urezki@gmail.com> <20240104162510.72773-5-urezki@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: > Hello, Zqiang. > > > > > > > // concurrent sr_normal_gp_cleanup work might observe this update. > > > smp_store_release(&rcu_state.srs_done_tail, wait_tail); > > > ASSERT_EXCLUSIVE_WRITER(rcu_state.srs_done_tail); > > > > > > - if (wait_tail) > > > + if (wait_tail->next) > > > queue_work(system_highpri_wq, &sr_normal_gp_cleanup); > > > > > > > I'm testing these patches :) , one question is as follows: > > Can we use (WQ_MEM_RECLAIM | WQ_HIGHPR)type of workqueue to perform > > wake-up actions? avoid kworker creation failure under memory pressure, causing > > the wake-up action to be delayed. > > > I do not have any objections in not doing that, so we can add. > > Thank for testing this! > I forgot to ask, is your testing simulates a low memory condition so you see the failure you refer to? Or it is just a possible scenario? Thanks! -- Uladzislau Rezki