From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) (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 304D047F57 for ; Mon, 22 Jan 2024 21:16:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705958182; cv=none; b=NNBOS1OF0dRfm9TbDBEH3z6I0qSHCtZj5g3BrtlPQL8/W5g/Wm5mLNqgbI99WGIoNrfEEFDq1TkazziN+HI7cgIU2JWXIWLshnOVexo4ubMkkzDptVhazCQi7RhNrNyrYemKXXgqVESEcwrSKExXbV2YdpDueeE/8mY392cBKXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705958182; c=relaxed/simple; bh=zMXc6tor4fJWUFbxItJ2+5r+CRBPP2/dvta/6uILgnA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XKpmXr9QdlTfizeNoSR15nzgqJgXCwvAIAX31gCrjuyI5qPTa8iImaimffo1P6FSaKrJpKZZameUhgn7VjZjv7kuBQL3Vqtnf7szKl6DdIPXRWkEkLS/gD0i0t91aufRIMTZIpcHSeag3I0rzqR8579qvZZyN4cCkoWwmL2L2BM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fastly.com; spf=pass smtp.mailfrom=fastly.com; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b=SaiTxQdK; arc=none smtp.client-ip=209.85.214.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fastly.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fastly.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b="SaiTxQdK" Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-1d71207524dso12484375ad.1 for ; Mon, 22 Jan 2024 13:16:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1705958179; x=1706562979; darn=vger.kernel.org; h=user-agent: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=WK/doAZyyGzQuUQ64pMN/IegoB0Y5GZJ/6bMRTJUZOs=; b=SaiTxQdKSvdfDHf7FsAVB4Up811/prozfadikTlsZcpgqyu//7JGkD7lZap1WTv3/3 zpsWEw/NFgolwwJgdoS3CQWtu6WWaltSUmnndO6I1eDYlP4mLNvPCOQ1U/7X2VPOVZCg mITcET3n22GHWVgtPIu4buWcJiSXEc5lOA120= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705958179; x=1706562979; h=user-agent: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=WK/doAZyyGzQuUQ64pMN/IegoB0Y5GZJ/6bMRTJUZOs=; b=YirDOepBq7rzD/lR6FC3gjU740igZ7ecKpE+JCgNbkeQ/ze69tg39pwsZXi3ioyG74 dF46RKpnW9y2+urhDJU1SbloT2OmWH2xKlKGtOO2D8s+vnrP815kZPKjGjLNuNqtVYGP GYPRFOWIDSLwxlMQ4apdbcgTaUUGZUUkaz4ZKmA83LtxcFn2ha/ARLrxsNM0puDextFj dPW/oW5nlgjcQKbw/xFJX1heYQxMJihqLKoUPTv2C9TH9nYIbOS22Rt1wNLNruypcDlF eTBjdTP1Vb4QJmZkuBHnc01hZvGxKIg2cYUJMqa1kWOw7FUQeCr9k/YZIGVuWye4bPLw rE1Q== X-Gm-Message-State: AOJu0Yyap9wwubnPqZiGWWfI/OsJ1nArWC+NYLXvfpPl298uQCEyaPZG RmpDG1jgPhV8+Hf4PX6DKuv4wkEENzZaD99pMMrH4Yue8jY/pJPlWDltsoZkptI= X-Google-Smtp-Source: AGHT+IHY6QTp3+L73kbC1yAy2VNJUlYykSfBPUTr4schnUh02OhLk1d1DJUhybB11UylKM92YKo7RQ== X-Received: by 2002:a17:902:e891:b0:1d7:599d:ed25 with SMTP id w17-20020a170902e89100b001d7599ded25mr1272345plg.39.1705958179526; Mon, 22 Jan 2024 13:16:19 -0800 (PST) Received: from fastly.com ([208.184.224.238]) by smtp.gmail.com with ESMTPSA id u4-20020a170902b28400b001d720c7ed48sm5693728plr.286.2024.01.22.13.16.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Jan 2024 13:16:19 -0800 (PST) Date: Mon, 22 Jan 2024 13:16:16 -0800 From: Joe Damato To: Christian Brauner Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, chuck.lever@oracle.com, jlayton@kernel.org, linux-api@vger.kernel.org, edumazet@google.com, davem@davemloft.net, alexander.duyck@gmail.com, sridhar.samudrala@intel.com, kuba@kernel.org Subject: Re: [RFC 1/1] eventpoll: support busy poll per epoll instance Message-ID: <20240122211616.GA1244@fastly.com> References: <20240120004247.42036-1-jdamato@fastly.com> <20240120004247.42036-2-jdamato@fastly.com> <20240122-erwidern-erleichtern-8a04080a4db3@brauner> Precedence: bulk X-Mailing-List: netdev@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: <20240122-erwidern-erleichtern-8a04080a4db3@brauner> User-Agent: Mutt/1.5.24 (2015-08-30) On Mon, Jan 22, 2024 at 04:25:01PM +0100, Christian Brauner wrote: > On Sat, Jan 20, 2024 at 12:42:47AM +0000, Joe Damato wrote: > > Add F_EPOLL_{S,G}ET_BUSY_POLL_USECS to allow setting a busy poll timeout > > per epoll instance so that individual applications can enable (or > > disable) epoll based busy poll as needed. > > > > Prior to this change, epoll-based busy poll could only be enabled > > system-wide, which limits the usefulness of busy poll. > > > > Signed-off-by: Joe Damato > > --- > > This should be an ioctl on the epoll fd, not a fcntl(). fcntl()s > should aim to be generic which this isn't. We've recently rejected a > memfd addition as a fcntl() as well for the same reason. OK, thanks for the review. An ioctl makes more sense, I agree. I'll rewrite it as you've suggested and send another RFC.