From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 5 Nov 2002 13:09:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 5 Nov 2002 13:09:24 -0500 Received: from mtao-m02.ehs.aol.com ([64.12.52.8]:36764 "EHLO mtao-m02.ehs.aol.com") by vger.kernel.org with ESMTP id ; Tue, 5 Nov 2002 13:08:57 -0500 Date: Tue, 05 Nov 2002 10:15:33 -0800 From: John Gardiner Myers Subject: pipe POLLOUT oddity In-reply-to: <20021031230215.GA29671@bjl1.asuk.net> To: linux-aio@kvack.org Cc: Linux Kernel Mailing List , lse-tech@lists.sourceforge.net Message-id: <3DC80AC5.6080705@netscape.com> MIME-version: 1.0 Content-type: multipart/signed; boundary=------------ms030009030702030206040504; micalg=sha1; protocol="application/x-pkcs7-signature" X-Accept-Language: en-us, en User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.2b) Gecko/20021016 References: <20021031230215.GA29671@bjl1.asuk.net> <20021101020119.GC30865@bjl1.asuk.net> <3DC30DED.6040207@netscape.com> <20021102045535.GA21356@mark.mielke.cc> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is a cryptographically signed message in MIME format. --------------ms030009030702030206040504 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Mark Mielke wrote: >On Fri, Nov 01, 2002 at 03:27:41PM -0800, John Gardiner Myers wrote: > > >>There's also the oddity that I noticed this week: pipes don't report >>POLLOUT readiness through the classic poll interface until the pipe's >>buffer is completely empty. Changing this to report POLLOUT readiness >>when the pipe's buffer is not full apparently causes NIS to break. >> >> > >These seems deficient. Does this mean that pipes managed via poll() are >not able to maximum throughput? > I could see this going either way, depending on the application. Holding off the POLLOUT readiness could improve performance by making sure that whenever a process is scheduled to write to a pipe the pipe has enough buffer to take all of the data. --------------ms030009030702030206040504 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIK7TCC A4UwggLuoAMCAQICAlvfMA0GCSqGSIb3DQEBBAUAMIGTMQswCQYDVQQGEwJVUzELMAkGA1UE CBMCQ0ExFjAUBgNVBAcTDU1vdW50YWluIFZpZXcxGzAZBgNVBAoTEkFtZXJpY2EgT25saW5l IEluYzEZMBcGA1UECxMQQU9MIFRlY2hub2xvZ2llczEnMCUGA1UEAxMeSW50cmFuZXQgQ2Vy dGlmaWNhdGUgQXV0aG9yaXR5MB4XDTAyMDYwMTIwMjIyM1oXDTAyMTEyODIwMjIyM1owfTEL MAkGA1UEBhMCVVMxGzAZBgNVBAoTEkFtZXJpY2EgT25saW5lIEluYzEXMBUGCgmSJomT8ixk AQETB2pnbXllcnMxIzAhBgkqhkiG9w0BCQEWFGpnbXllcnNAbmV0c2NhcGUuY29tMRMwEQYD 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