From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f51.google.com (mail-lf1-f51.google.com [209.85.167.51]) (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 C1CAE1DEFEB; Thu, 27 Feb 2025 17:43:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740678240; cv=none; b=djFYh5idSOCgfjnb6ElcZS0sDPqr5PsRzCXXF6TTR3UoDRosouHkh/PuLVjK/KgTIaSfivt9Lusl3GBgqKUceZ/mqCp7fLLCe18Ur1nY2cq8zw7bfiLdGc6x8RAvEYBg5K85AB07vctdVAa8EVyskkn8pYQNurEwjpwGTpeRWU4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740678240; c=relaxed/simple; bh=CJMTauSRCEWnlEAWxjoYy7NZ0L4FJshH0qmAshtRy2E=; h=From:Date:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nJbMGNdBbKiuUhdOpR/Hx81TalK+T2JGYmFoxpkL64eSHkiVGe+RiCs96hncui6GONxoFq+/vXUPxxH/JoQ1GWn9nrokfcKl5u2g5iHyXwWhy9b0LEKmidAKW3ZPCthzMtOkrZ5gmp/yh3KG2utNgkuELpaq6hdyX5luQHiWlkE= 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=Zgw/CVow; arc=none smtp.client-ip=209.85.167.51 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="Zgw/CVow" Received: by mail-lf1-f51.google.com with SMTP id 2adb3069b0e04-54943bb8006so1210409e87.0; Thu, 27 Feb 2025 09:43:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1740678237; x=1741283037; 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=X3vEaodisrvKcNhPG/ww/1OyCGncwG4JxfefrvjSq2w=; b=Zgw/CVowjlcw9KCeqDPZZl/bZ0diW6phcVyDgz7Md4PKbgSACu44zDGKiCd9/tf6sg 4QMfNCOdfbuk7bcYtKxjl8OYP2SeMjpFWE4OWVw9drvNYhUbDPQOeOKAVEOz6TO/Ko6+ sUNIInHV26wuKMPRzDtwxrSScx3GG5ekEjLONUVkcndMl2XGY8oCBErImxwZ1oFcPH0A ogULPUBr0nmNR0LFiEnj0lhtNfXgCvY0VTkjcywlk6zz7ad4Re2rVpXGSzU/NGeoHhns NL6D9ADP+wFdlQ5ic2CIziK3PFki/fV5sl1f+yNUDfpbh7KhtWijeJfsUfRp6Q728QnX qLvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740678237; x=1741283037; 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=X3vEaodisrvKcNhPG/ww/1OyCGncwG4JxfefrvjSq2w=; b=D6qjrNZKF0xz/TWF6WKzSP9Nlw+408Bdof3Uvukp6yksqL/7ks1eltTsKimax3jZu7 AgXWiQCEsuMig/OJHSRpcTxw5hB0JUn+LsA6oVmKqPqVJcBpRVHOYsmLVKwJTlK/qIQG 4kXzr19a1rEPdqZcnDWr3oNt/EvuosZh46eYah2AnXC1ReVf8P9jup/5XwwWSc4iIn2J j5PcbJlzRf4GvIKc1TOpyvxK3LoB6OZmvYzSRTLfwLekLJDaiaoxZ3TO6zAVAxDmCfy+ mrxvyezYIQ4ITMpBH9nosN8um9cn4QH0FUElFRTgOmrpjTRBg+ldtHVcIlsd6j2eOhzp rsbw== X-Forwarded-Encrypted: i=1; AJvYcCUT6JQG5+b+wKq20fUf7O5XcSzoIumWn4gNMZjJ7xbV2XLCjEpvXqD7P8O0mSWQhnvCettA@vger.kernel.org, AJvYcCVrbq8emfwmz+T5R5nDYrg8bnTVpILCZoMUDCQFZ1Hs5KtCyaeRNMWro+F3c3MZqt9RzJmTZjTJ6SrtJBs=@vger.kernel.org X-Gm-Message-State: AOJu0YzgV5tSrYYEjoFU8Mid/OQJWDsCTsBfbWXFx8YII+qg5KGblZBd JzGiTdQzoeJUXgeFw+Eel3HtG+OV2J42OOa5xf06cgsH4c0n1gr4 X-Gm-Gg: ASbGncsoJduz9By7kVZtGPcFmZQZf6y4ZZyAywms3lXm/tbhIow5nHxObzZIdQmhgGb BLwak98B2yl0FPz+WIs/Gl2DQB2ANVF4nenb43KHrjPazLV7LyNoMQFt5rxptIg5vTpO5/ewJdG jS6eoMQsKsogodtaVXfzTLqXzCwN2rO1wahsUDaUP9cZNtDmhsbhxmwCBBazLOub4Cmp4pMYTh8 7Pa8lhN46wRjsnpRuRt3cUD4CSr/2fQka0fm4nYeK83qmUreM3mlB4mwkaMCi+esLR7qFOcv9Mc LdXD4n18hm2bGmRns3z2OjEofJKAGieT5P+7xxGhPhJ55Ejg X-Google-Smtp-Source: AGHT+IGLQeTGJpG2m7C1VeIlUSZuQjnIL1ku5l1tB/izF3+EkRVVl1HYHlLSBB4oXrSJjG74ftT/oA== X-Received: by 2002:a05:6512:281d:b0:545:5d:a5d8 with SMTP id 2adb3069b0e04-5494c10c5efmr143109e87.7.1740678236456; Thu, 27 Feb 2025 09:43:56 -0800 (PST) Received: from pc636 (host-95-203-6-24.mobileonline.telia.com. [95.203.6.24]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-549443cd45dsm215760e87.252.2025.02.27.09.43.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Feb 2025 09:43:55 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Thu, 27 Feb 2025 18:43:53 +0100 To: Boqun Feng Cc: "Uladzislau Rezki (Sony)" , "Paul E . McKenney" , 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: Hello, Boqun! > 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. > Thanks! > > 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? > Probably. But i do not remember that i got a review from Paul. Might be wrong and have missed that :) Anyway, thank you for adding. -- Uladzislau Rezki