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 99CB88564B; Wed, 7 Feb 2024 19:04:39 +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=1707332679; cv=none; b=mvzQ1RzPJmdvxr5YmpEn2LYaJODwtX5/OFDGbM+qJc97g3bw0Ri0AxkZX+ldxakc1nV+ReEvHtK1yaFxWlCO0p9Cr010pvGNDn4g2hnIjkzMEAmbMJjng6LtvucLLcVaYUF11oNZ54c9Zs9NnGBBnfAt0zncM9EG2o4f+YPdeQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707332679; c=relaxed/simple; bh=5GVhqpjuJPE3FvDUZWAwDUtgj5KWUa1cTo/8uxteTSY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qgiq3wyX8djdFoMGGhHa9trBFU7deowuaZrzs86mRqqvxeYeMjzj7c01GDNKdv67iOOiEGIf4kWWSLgKr3xn1Ygk0zznlmO+Vm4BWqujF552JFQ6Qo0uiq09xkvuHltpu3z4jYkT3c/iXloDmTMKDk6zmNsbWWS5+IHyMOdkvvI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ENQrnzkO; 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="ENQrnzkO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F337C433C7; Wed, 7 Feb 2024 19:04:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707332679; bh=5GVhqpjuJPE3FvDUZWAwDUtgj5KWUa1cTo/8uxteTSY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ENQrnzkOPesZKqiDU0cwLn6XoCVLAjhIas4QUugytVYKxIG6Ba3AAqFcM4GdT4lKE ZIfO4DJkgQ2SumZp9LXEi1kNi30mL3Uc/OnlYY+cq7ElPW8rEFM2oaARX/iHE5iQXF l0LSvClRKd072SrfoHcrqBEvIm6rmJa3ALLMeloOH9BE6HIC7M/PFr1u9X6RkoLyJE d6rasc/zNnMTcS7TOx95EfuDYryAmxUEXZfrKk5TAXjOE3w7wI7r8TASZjU0md0wxM QgGwhSp1i4pwA3EiydfHLf969TbHVr9X9bKjDRjFz9cRJfYaBxu9JvbXmn5NkCL72q rPBnlttOAE8vw== Date: Wed, 7 Feb 2024 11:04:37 -0800 From: Jakub Kicinski To: Joe Damato Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, chuck.lever@oracle.com, jlayton@kernel.org, linux-api@vger.kernel.org, brauner@kernel.org, edumazet@google.com, davem@davemloft.net, alexander.duyck@gmail.com, sridhar.samudrala@intel.com, willemdebruijn.kernel@gmail.com, weiwan@google.com, David.Laight@ACULAB.COM, arnd@arndb.de, sdf@google.com, amritha.nambiar@intel.com, Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)) Subject: Re: [PATCH net-next v6 3/4] eventpoll: Add per-epoll prefer busy poll option Message-ID: <20240207110437.292f7eaf@kernel.org> In-Reply-To: <20240205210453.11301-4-jdamato@fastly.com> References: <20240205210453.11301-1-jdamato@fastly.com> <20240205210453.11301-4-jdamato@fastly.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 5 Feb 2024 21:04:48 +0000 Joe Damato wrote: > When using epoll-based busy poll, the prefer_busy_poll option is hardcoded > to false. Users may want to enable prefer_busy_poll to be used in > conjunction with gro_flush_timeout and defer_hard_irqs_count to keep device > IRQs masked. > > Other busy poll methods allow enabling or disabling prefer busy poll via > SO_PREFER_BUSY_POLL, but epoll-based busy polling uses a hardcoded value. > > Fix this edge case by adding support for a per-epoll context > prefer_busy_poll option. The default is false, as it was hardcoded before > this change. Reviewed-by: Jakub Kicinski