From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (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 E8DAC23AB; Sun, 1 Sep 2024 07:01:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725174067; cv=none; b=p4qzZK4M9bpb0fXqD5U3+Vn381y+IpH7xDk012KdpmDESQ5H4WXNZk8IN9aDYF1o1HXhs4y2zI50X14hWV0WMak9r5R1ifKANI6FNSeG9VC0I53bHDADANF2kb1Y1IHhNvxqL6erWwlJsCSsYQl9fYEqv9Zoq2wKW3xndh5Sq54= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725174067; c=relaxed/simple; bh=A/Aqg0idiR9dTPMDqDXHWk7lNlNc328DQSDoeUkSoqA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mdXI3fG/WKj07eCi+07ybYhIh3sfdMnFfGYaPRu+LMyR6kZqNO6msCiVmNILICzYJa0IMku3AZYvz8jLg6zhgXT3L5ndZJ1h+TZDjB2GHNnQh67ILFR4i5MrVwnskE0l8xTrY38SHY3/RLPSDjRgkelho76JAXTdYsemdW22Cdc= 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=IHwrnmYZ; arc=none smtp.client-ip=209.85.210.172 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="IHwrnmYZ" Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-715cdc7a153so2280031b3a.0; Sun, 01 Sep 2024 00:01:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725174061; x=1725778861; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=SOR3mKfIagEi6CTRnZb5FU+cHEbUu8vgBTPn6H57S0w=; b=IHwrnmYZ9Nzjh1G6OSTBehyPOkQUp2NlQcdi4AobZ5uasLDlTrN13it+ZmOqmLtEal ZEA4ayry2hnciGIgNNTOY/e/qIshjHUpKY0fQBokQKXFBpWUK3HirzFL8jnD0B2oJySv WupTvSp95gLnYmigHFQqXP2Akw+w360XyyqPivzeYRIrph1oRLQFHFw1o8n7TAqnPLVF LhjcdA+w79ZS+WckxfqsTcNVBNNis4LRmHyEorZa9kzYQLtOzhU5bCiatIkqgv04nF54 k/VK2PdYsLPnrkZCKyeKTB+evhCpYP1mf+4uC1umz3VqsObLbqZ7H1AdbIS6fmhBuZ3X n4ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725174061; x=1725778861; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=SOR3mKfIagEi6CTRnZb5FU+cHEbUu8vgBTPn6H57S0w=; b=uX/wusUwHo3Ywb6qBAl8fYZyo2LfYvG7dFzZgrxnQTKLC/4jcS2AvquNt0xcB+k18l bHqmZaSIiQ5a5mLTWPlryabBBiT+KNGD3WW09QPQSoBitv701B1Ra1nZkTiWy1UEbVdb yQTy9vlOw/dkzhxhantYkG6aVQjN/v/2ehooMejmONXq3aE77Lf+OWllZfN5yuoPpEjG +C74EOvt6yHI9NYxTwMUsq4gYHkEIBAF2JdB49c26anGuPf6lSp222sgCuly+Sw5w+Cr xv6rot8ek1dzD4WnU4x7RBMIeMEJQndlY/L0TojU9bpMS2ijm4eSlFa3uqcz3ul81Q32 raKg== X-Forwarded-Encrypted: i=1; AJvYcCUqBX5eOKg8TjGAyu6RmCAy5Lt1apUdr0cgkWT+fojs8MoxAePdDoDvOyojpy6manIeBc+5LtTsxWlAF/L5@vger.kernel.org, AJvYcCV+mtNXQ1xjhJZqsChf1LMZRgQQgmgeVM2o+U5nTAseWI1gFb9CyZOfuHOg1Dd/T8zy3tdQWvjtcBtSf2iF@vger.kernel.org X-Gm-Message-State: AOJu0Yzly81dY1elNUutSvS0F/nnjdU7Vnj0J3MK20lt7MiCrQt5fXNJ g9sVS62eNJSHM1mqJC/xnaEHkrfYtZA1XhjRRCR9IvSReWONo9fD16G+2Q== X-Google-Smtp-Source: AGHT+IHJTYwzbEkXY0gErCW2BEzpwy27lw/w9KBdaWJFALcVgx8vsd0l/xw1HxWwQSmYtj36c2I+2g== X-Received: by 2002:a05:6a00:8d6:b0:714:228d:e9f2 with SMTP id d2e1a72fcca58-717000c75demr10668308b3a.3.1725174061057; Sun, 01 Sep 2024 00:01:01 -0700 (PDT) Received: from visitorckw-System-Product-Name ([140.113.216.168]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-715e56e3f95sm5191660b3a.176.2024.09.01.00.00.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Sep 2024 00:01:00 -0700 (PDT) Date: Sun, 1 Sep 2024 15:00:57 +0800 From: Kuan-Wei Chiu To: imandevel@gmail.com Cc: jack@suse.cz, amir73il@gmail.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] inotify: set ret in inotify_read() to -EAGAIN only when O_NONBLOCK is set Message-ID: References: <20240901030150.76054-1-ImanDevel@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: <20240901030150.76054-1-ImanDevel@gmail.com> On Sat, Aug 31, 2024 at 11:01:50PM -0400, imandevel@gmail.com wrote: > From: Iman Seyed > > Avoid setting ret to -EAGAIN unnecessarily. Only set > it when O_NONBLOCK is specified; otherwise, leave ret > unchanged and proceed to set it to -ERESTARTSYS. > Hi Iman, Have you checked the code generated by gcc before and after applying this patch? My intuition suggests that the compiler optimization might result in the same code being produced. Regards, Kuan-Wei > Signed-off-by: Iman Seyed > --- > fs/notify/inotify/inotify_user.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c > index 4ffc30606e0b..d5d4b306a33d 100644 > --- a/fs/notify/inotify/inotify_user.c > +++ b/fs/notify/inotify/inotify_user.c > @@ -279,9 +279,11 @@ static ssize_t inotify_read(struct file *file, char __user *buf, > continue; > } > > - ret = -EAGAIN; > - if (file->f_flags & O_NONBLOCK) > + if (file->f_flags & O_NONBLOCK) { > + ret = -EAGAIN; > break; > + } > + > ret = -ERESTARTSYS; > if (signal_pending(current)) > break; > -- > 2.46.0 >