From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f169.google.com (mail-qk1-f169.google.com [209.85.222.169]) (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 9BDCC136351; Thu, 27 Feb 2025 17:30:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740677417; cv=none; b=Au/Mprsg/rvA34RnaMBJXOUTYPjnRN0dct/GL26inpzBisympmhtFwe9471ci828R23jDRpPhifsHMCLm145YdEX52hkt7EIQshNRVc6DAId5X+v89BA8oZsKPFy1nbwG4MoswTy4k8F7V2Ka2VBM4ZL/pkKfs7ZNaIieqyHm/o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740677417; c=relaxed/simple; bh=BHOmUMRksJWGkPGQguX9AGezCQ1EireXEQhlLKUOn+4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oUgtLseOqB3MVaUIHMyKJwMvNWyoC47CrsXnqIiZPImCCNcMw7RE17DvCcJCOwVjmQYnoDWJ02mUKOyLYRorZ7KzKMaf019+HCaJPxT2bAnNvbXy/Ru8KeAdNf4BT4UKcx6Un1RjLpv5zUwvkG8e1Wl6sWqCp1KN/oIU/AzoChA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=WF5hv/jj; arc=none smtp.client-ip=209.85.222.169 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="WF5hv/jj" Received: by mail-qk1-f169.google.com with SMTP id af79cd13be357-7c07cd527e4so111682285a.3; Thu, 27 Feb 2025 09:30:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1740677413; x=1741282213; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:feedback-id:from:to:cc:subject:date :message-id:reply-to; bh=+ncAr0i2yaCNPOat1iqqfGrGLU6UJ1TbQz5tFfMPH0g=; b=WF5hv/jjMLiVzAPId0v2EOLpwfTh19vdQcTYZhloWx5dNK2k270bOmZAq5As4hJ1A9 mNAwbyjC0zsu23cQSuOlw38JT+IuqgUOj57kdmfwlIL8xrEbGOqbdGkhuiP76QFnsWjk d0NwgAhQn1cma6x49cOvXonm71TreBbz06vGcvMPUzCpCA4wuNI+QwhPHMlfFPeIVlTQ h2AKe0DM7CbMa9+TuIMWlF7AWGiDoxXInDnjl4le+nSLaF9oLadxSigMuuAAtNovtV9/ QnWEwqEeuzFfj3ob1Jf5Y0WINRKEQNBs33cz3aLHhEydrLyXTxSkO9wrvChdUUTWxb3Q NHqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740677413; x=1741282213; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:feedback-id:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+ncAr0i2yaCNPOat1iqqfGrGLU6UJ1TbQz5tFfMPH0g=; b=G8EzVmdu1CcK8LbSiPV+YoDdCAWib17IKa16lLZpPXqSnWm/eLzMUwaLnySJvvDteV RZmW1bOBHIacZ+BT+fOEul9/CqYvleYeb/LH+WCRjva6HjInq6hQusfQovuA+wwSmB3v lFGZtT9hg2RnD8vPVeEbo90vZauTXFBYGj0L9ny/fuwgLMIrAoou5RqydQyAVrzELdN8 RffcYQjMCW+cPJPTzIbiLMCrX9IDqCT3FXNkAAZZKYdDUOkIh5hYpe5q+0GgnlxxG3xF gTkqxtM/mdTxHcycEDvpx0JB2RZSaqc9gN3UnJ+yUhW5gqCMr/ROpu5WSLdwABp5wyhG vwlw== X-Forwarded-Encrypted: i=1; AJvYcCWwaosvoQHSzQuXvka/GgTN9jqDsBpde7YdhiOpxpIuhKuRb5J+to3zz5f212hh2wDi5TgK@vger.kernel.org, AJvYcCXNePfDhAikQhicvM5vgwW3n+E0MBC/glcb7VlNih3nrkfQCo7Jvl2jUWK+XuSGYozc6DavJc1OSv0bdv0=@vger.kernel.org X-Gm-Message-State: AOJu0YzbEzt/rWDURhIkTP7QPtS5RuIc629Cvcip5zrYu1taw66JKm4U BOKS52Zhx61OuKkaBPU+neirAte+m0/igGMAu1Xuf4HKns5s0QS+ X-Gm-Gg: ASbGnctj6pHPsiuQqPnZbtCuXMGADA4t6hoXtTXFwTErvmVGT4EwVxPOmLzepUfkyyz GtlTeCMtli3xtjw6k10YJ7PV2hIKiii+O8YDi0HwgBg61XZexkWXzNhqMsxDc+RcD89Bxvxt/TF S0JqgU/GD03qA1J9CXH63j7NlelUnZK+dStgN1ZpRRjMm2k+OQDDO1FdSLrbBh5R+L3F/xBxO8N gxScoEjhL3KUTXdJarBH10GyWgS4g3lsY6SpH/x63HseOn1i44JdBP5We5nevzQubbHksZvmrBi EVHKk3DYr0YAed0qIt8rUhNN8uwyLL9JLUnOiB73qbbKZl3a4YvwW9ScudaYUY2JKwFxBTQJEit ASKpovM0zik3LBuU9 X-Google-Smtp-Source: AGHT+IEhqRePoIEaEEW0l4JynfwuD/1O+VvhzuB6mR89VzP+NE6CE3gvCV8+gHkU6kXrYKP0OaNTog== X-Received: by 2002:a05:6214:2462:b0:6e4:4331:aae6 with SMTP id 6a1803df08f44-6e8a0d9990emr3818696d6.39.1740677413129; Thu, 27 Feb 2025 09:30:13 -0800 (PST) Received: from fauth-a2-smtp.messagingengine.com (fauth-a2-smtp.messagingengine.com. [103.168.172.201]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7c378dacd0bsm128276585a.90.2025.02.27.09.30.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Feb 2025 09:30:12 -0800 (PST) Received: from phl-compute-12.internal (phl-compute-12.phl.internal [10.202.2.52]) by mailfauth.phl.internal (Postfix) with ESMTP id 3E6351200068; Thu, 27 Feb 2025 12:30:12 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-12.internal (MEProxy); Thu, 27 Feb 2025 12:30:12 -0500 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdekkedtjecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdp uffrtefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivg hnthhsucdlqddutddtmdenucfjughrpeffhffvvefukfhfgggtuggjsehttdertddttddv necuhfhrohhmpeeuohhquhhnucfhvghnghcuoegsohhquhhnrdhfvghnghesghhmrghilh drtghomheqnecuggftrfgrthhtvghrnhephfetvdfgtdeukedvkeeiteeiteejieehvdet heduudejvdektdekfeegvddvhedtnecuffhomhgrihhnpehkvghrnhgvlhdrohhrghenuc evlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegsohhquhhn odhmvghsmhhtphgruhhthhhpvghrshhonhgrlhhithihqdeiledvgeehtdeigedqudejje ekheehhedvqdgsohhquhhnrdhfvghngheppehgmhgrihhlrdgtohhmsehfihigmhgvrdhn rghmvgdpnhgspghrtghpthhtohepuddtpdhmohguvgepshhmthhpohhuthdprhgtphhtth hopehprghulhhmtghksehkvghrnhgvlhdrohhrghdprhgtphhtthhopehurhgviihkihes ghhmrghilhdrtghomhdprhgtphhtthhopehrtghusehvghgvrhdrkhgvrhhnvghlrdhorh hgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdho rhhgpdhrtghpthhtohepfhhrvgguvghrihgtsehkvghrnhgvlhdrohhrghdprhgtphhtth hopeiiiihqqhdtuddtfedrhhgvhiesghhmrghilhdrtghomhdprhgtphhtthhopehnvggv rhgrjhdruhhprgguhhihrgihsegrmhgurdgtohhmpdhrtghpthhtohepjhhovghlsehjoh gvlhhfvghrnhgrnhguvghsrdhorhhgpdhrtghpthhtohepohhlvghkshhihidrrghvrhgr mhgthhgvnhhkohesshhonhihrdgtohhm X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 27 Feb 2025 12:30:11 -0500 (EST) Date: Thu, 27 Feb 2025 09:30:10 -0800 From: Boqun Feng To: "Paul E. McKenney" Cc: "Uladzislau Rezki (Sony)" , RCU , LKML , Frederic Weisbecker , Cheung Wall , Neeraj upadhyay , Joel Fernandes , Oleksiy Avramchenko Subject: Re: [PATCH v4 3/3] rcu: Use _full() API to debug synchronize_rcu() Message-ID: References: <20250227131613.52683-1-urezki@gmail.com> <20250227131613.52683-3-urezki@gmail.com> Precedence: bulk X-Mailing-List: rcu@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: On Thu, Feb 27, 2025 at 09:26:40AM -0800, Paul E. McKenney wrote: > On Thu, Feb 27, 2025 at 09:12:39AM -0800, Boqun Feng wrote: > > Hi Ulad, > > > > I put these three patches into next (and misc.2025.02.27a) for some > > testing, hopefully it all goes well and they can make it v6.15. > > > > A few tag changed below: > > > > On Thu, Feb 27, 2025 at 02:16:13PM +0100, Uladzislau Rezki (Sony) wrote: > > > Switch for using of get_state_synchronize_rcu_full() and > > > poll_state_synchronize_rcu_full() pair to debug a normal > > > synchronize_rcu() call. > > > > > > Just using "not" full APIs to identify if a grace period is > > > passed or not might lead to a false-positive kernel splat. > > > > > > It can happen, because get_state_synchronize_rcu() compresses > > > both normal and expedited states into one single unsigned long > > > value, so a poll_state_synchronize_rcu() can miss GP-completion > > > when synchronize_rcu()/synchronize_rcu_expedited() concurrently > > > run. > > > > > > To address this, switch to poll_state_synchronize_rcu_full() and > > > get_state_synchronize_rcu_full() APIs, which use separate variables > > > for expedited and normal states. > > > > > > Link: https://lore.kernel.org/lkml/Z5ikQeVmVdsWQrdD@pc636/T/ > > > > I switch this into "Closes:" per checkpatch. > > > > > Fixes: 988f569ae041 ("rcu: Reduce synchronize_rcu() latency") > > > Reported-by: cheung wall > > > Signed-off-by: Uladzislau Rezki (Sony) > > > > You seem to forget add Paul's Reviewed-by, so I add it in rcu/next. > > Would you or Paul double-check the Reviewed-by should be here? > > I am good with keeping my Reviewed-by tags. > Thank you! Regards, Boqun > Thanx, Paul > [...]