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 401FA126F23; Wed, 7 Feb 2024 20:11:25 +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=1707336686; cv=none; b=kXnlNkKoYK7XiW16OOGAwUa9DwHOA4znJdnsOLH4ss69pLV5fMKB7Fxygz0ACTPofPfT8mVBZzbxCB3hoplLcOynv5bCWuv5frkXHruA3P+StHBEcGCzvRmf1CjHhck4UvCgw+cxmmNZA8fMGBX2sdLeu8FwrOyRx+V+fqirrAY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707336686; c=relaxed/simple; bh=QXN87N7aKQ5QhHocBoZZ4H7bNqPh3YgQREojYkDT/Vo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uL+Od+/AKE03TBkos98mhUep9JiRQJHj+wvmkKXR1aboD1VU+anLX+kElaE8UaE5J4RIteOJ22nWDUOvdn5857HMHIShlHrQ17wOGEcX8GQU8gW3nw142NiXmJIQGFQkMYe9JK80Gmxpyj+OFVfQd9GSS/JL5hmH8yduXx5n80E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dcmA/0pz; 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="dcmA/0pz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0E0AC433F1; Wed, 7 Feb 2024 20:11:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707336685; bh=QXN87N7aKQ5QhHocBoZZ4H7bNqPh3YgQREojYkDT/Vo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=dcmA/0pzJCuJimekNhCfo931qGd7ni5BMoqgHmGXnqAoAaFsiOGGwd4+j/YOSZW9m b8czhw//KWjA0wtG2iPcyLqpsheF8BIDFPHGI2PqPhtYh+EytyriUhZKjox9mNnqYG E4l4l3XhNm5Wva0YrmeEiQSJyAkhbKG4em4VXvmOJjubD+n7jSmjhUrf/PsSiZuKj7 9u3sluMv+mDHiy0KBEZoC3lmX5c3MZMA6z+5u3pwnS6z3r6gsewWJRSrCgeI6ZxoAd vC9oU17Qu+hxR7047V4LHGAcRY1Ifa8BNfYQvMflMbkSe7ABr/8DNFTz8wQRjFYQj1 h5eFZZsOkLAfg== Date: Wed, 7 Feb 2024 12:11:24 -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 , "open list:FILESYSTEMS (VFS and infrastructure)" Subject: Re: [PATCH net-next v6 1/4] eventpoll: support busy poll per epoll instance Message-ID: <20240207121124.12941ed9@kernel.org> In-Reply-To: <20240207191407.GA1313@fastly.com> References: <20240205210453.11301-1-jdamato@fastly.com> <20240205210453.11301-2-jdamato@fastly.com> <20240207110413.0cfedc37@kernel.org> <20240207191407.GA1313@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 Wed, 7 Feb 2024 11:14:08 -0800 Joe Damato wrote: > > Why do we need u64 for usecs? I think u16 would do, and u32 would give > > a very solid "engineering margin". If it was discussed in previous > > versions I think it's worth explaining in the commit message. > > In patch 4/4 the value is limited to U32_MAX, but if you prefer I use a u32 > here instead, I can make that change. Unless you have a clear reason not to, I think using u32 would be more natural? If my head math is right the range for u32 is 4096 sec, slightly over an hour? I'd use u32 and limit it to S32_MAX.