From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A48ED41210; Mon, 22 Jan 2024 15:25:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705937107; cv=none; b=mJ1kjrvoMTECDpuUWNLYP1V1EJfuCo/6ZWUIsfa05cceywaqlvfKbt5Q12UoSziVrNc25MmXsrtGZtN7YE3byL1ZKEYl6+Z0LfDiWsCu61oqdJf1KlM7pDNCmEbH06CWVjF1IgND3Vka2/EkDfA/+/ujK4ySthu0CdbKUH5eblM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705937107; c=relaxed/simple; bh=uQjaKfpOsy59BldaTOx7UUJOln9p/JBZ5qFpOPOj//g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YHg6ZY8gX7E4NppqvzKzlNrEdJVGWDMdzx9VjmInqc3KugzTs6bFte3mPdDRguvTfHMuF29XrFaCknXWlh92B/1H6ad7iUXcJMbyeU8YjXnXy3J4JwCRiQ4TdzTPOngeEvbQcy88hJXYw8zN5LpvFOvxey7fVKhMHvePiMwiznI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W2s87Plc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="W2s87Plc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1454BC433F1; Mon, 22 Jan 2024 15:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705937107; bh=uQjaKfpOsy59BldaTOx7UUJOln9p/JBZ5qFpOPOj//g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W2s87PlcBBQgG38hGiE77fLDeUK2SsJuqEWSUpS7anXa0zvPd0YfhQBtaAq9q4LnD wpynDeqFv62dNga4fTQDpPubw+eDwBstZQ4qEmY66rZAdoAGgQwOloK6C7f4jchD5X sdwaSgS8IanBaY9XlpnLZxxnlb/DP6gM0KlrzMLCrExWtEhkrdwiTiRqNX3sjNJytb BHd6aA296DPnt1VHJz5aa9SI0W9MNtaHCVt4yrbYauP2GggMC9kXndxsvHbT2DiTBt pnlzF+XxECAToHUsXPO5+2iCWvjrbKvZwV9sV5DirJKc6waVVnGfDPXJRJ2/2cMco+ m16PaOlAoJICg== Date: Mon, 22 Jan 2024 16:25:01 +0100 From: Christian Brauner To: Joe Damato 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: <20240122-erwidern-erleichtern-8a04080a4db3@brauner> References: <20240120004247.42036-1-jdamato@fastly.com> <20240120004247.42036-2-jdamato@fastly.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240120004247.42036-2-jdamato@fastly.com> 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.