From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2007468-1516291046-2-5558682861369055254 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1516291046; b=EwjFiwK7KH1thsBLvRDx8DoEzO9tg0Fgj017ZxgTjluOBZc aiN3ohY2kIJ+NNIsmEi0EnEgdOnhU9jNGxZfQ1C/Tj47YQnohWDiC39DF6Jihlzx UPhaaHgUTKj7tg+If9mxdighO3/9lMNHeyDkaUfbts0nyze6jfP+uQmJlpMxo8fI oDF8xUaXH/DV6bcN590YS39Q4mCBnUh+Q4L09tiP/4FxVOyrhw9QxUiB+JBdXTQN iPDUBB26CkGRTFnGxX79zX8MRGEaQcAteHC1PUjZb0314Qx1Wy/uty5huVV5NHuu HuQjeOxbJFg9iqF5ZAHiunpbwvZl0uuyAFx67sQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:references:date :in-reply-to:message-id:mime-version:content-type:sender :list-id; s=arctest; t=1516291046; bh=PSLvrxz9vDBaUw6dPHKeetXaf1 vRb1wi48RiM3MPzKw=; b=gNtKZ5UcA+jPyIRt/e4XYpq/nqhQlZOWk4bqgTf5Nb +bsGvH4KlUM0Bakk+LOYWzikdbXRHpoI2v2j2WlE8xf2KVV4e0Awue4zEUXI+kFc RGrBz/ubUykEUhgTlFopbZSJOaOuXo9wY5wInu4ILEoY/YH3uTzz3ixDJ8rFg9ce ypIifgchpY/RRm6WUjyF85TbCmwCWZeueOrqe3qIXtu3cKgU/Z/ijsPHBox/ID9p u5u9qvxZwjm43lOIuekZiJIQysDZLCSlt1KfI/prr0N3lBQozCNLNFljZpwoVCSk Hr9/kk7LVKE0jec5Jsiv59+/EE7BYIMIveIcGhyXtDwg== ARC-Authentication-Results: i=1; mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes Authentication-Results: mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933066AbeARPzw (ORCPT ); Thu, 18 Jan 2018 10:55:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56572 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932668AbeARPzj (ORCPT ); Thu, 18 Jan 2018 10:55:39 -0500 From: Jeff Moyer To: Christoph Hellwig Cc: viro@zeniv.linux.org.uk, Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: aio poll, io_pgetevents and a new in-kernel poll API V3 References: <20180117192742.710-1-hch@lst.de> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Thu, 18 Jan 2018 10:46:39 -0500 In-Reply-To: <20180117192742.710-1-hch@lst.de> (Christoph Hellwig's message of "Wed, 17 Jan 2018 20:27:06 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: FYI, this kernel has issues. It will boot up, but I don't have networking, and even rebooting doesn't succeed. I'm looking into it. -Jeff Christoph Hellwig writes: > Hi all, > > this series adds support for the IOCB_CMD_POLL operation to poll for the > readyness of file descriptors using the aio subsystem. The API is based > on patches that existed in RHAS2.1 and RHEL3, which means it already is > supported by libaio. To implement the poll support efficiently new > methods to poll are introduced in struct file_operations: get_poll_head > and poll_mask. The first one returns a wait_queue_head to wait on > (lifetime is bound by the file), and the second does a non-blocking > check for the POLL* events. This allows aio poll to work without > any additional context switches, unlike epoll. > > To make the interface fully useful a new io_pgetevents system call is > added, which atomically saves and restores the signal mask over the > io_pgetevents system call. It it the logical equivalent to pselect and > ppoll for io_pgetevents. > > The corresponding libaio changes for io_pgetevents support and > documentation, as well as a test case will be posted in a separate > series. > > The changes were sponsored by Scylladb, and improve performance > of the seastar framework up to 10%, while also removing the need > for a privileged SCHED_FIFO epoll listener thread. > > The patches are on top of Als __poll_t annoations, so I've also > prepared a git branch on top of those here: > > git://git.infradead.org/users/hch/vfs.git aio-poll.3 > > Gitweb: > > http://git.infradead.org/users/hch/vfs.git/shortlog/refs/heads/aio-poll.3 > > Libaio changes: > > https://pagure.io/libaio.git io-poll > > Seastar changes (not updated for the new io_pgetevens ABI yet): > > https://github.com/avikivity/seastar/commits/aio > > Changes since V2: > - removed a double initialization > - new vfs_get_poll_head helper > - document that ->get_poll_head can return NULL > - call ->poll_mask before sleeping > - various ACKs > - add conversion of random to ->poll_mask > - add conversion of af_alg to ->poll_mask > - lacking ->poll_mask support now returns -EINVAL for IOCB_CMD_POLL > - reshuffled the series so that prep patches and everything not > requiring the new in-kernel poll API is in the beginning > > Changes since V1: > - handle the NULL ->poll case in vfs_poll > - dropped the file argument to the ->poll_mask socket operation > - replace the ->pre_poll socket operation with ->get_poll_head as > in the file operations > > -- > To unsubscribe, send a message with 'unsubscribe linux-aio' in > the body to majordomo@kvack.org. For more info on Linux AIO, > see: http://www.kvack.org/aio/ > Don't email: aart@kvack.org