From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 003B4C43444 for ; Thu, 17 Jan 2019 12:48:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC98A20859 for ; Thu, 17 Jan 2019 12:48:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728023AbfAQMsS (ORCPT ); Thu, 17 Jan 2019 07:48:18 -0500 Received: from mx2.suse.de ([195.135.220.15]:37526 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726065AbfAQMsS (ORCPT ); Thu, 17 Jan 2019 07:48:18 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C5C4EAD7F; Thu, 17 Jan 2019 12:48:16 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 17 Jan 2019 13:48:16 +0100 From: Roman Penyaev To: Jens Axboe Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-block@vger.kernel.org, linux-arch@vger.kernel.org, hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, linux-block-owner@vger.kernel.org Subject: Re: [PATCH 05/15] Add io_uring IO interface In-Reply-To: <20190116175003.17880-6-axboe@kernel.dk> References: <20190116175003.17880-1-axboe@kernel.dk> <20190116175003.17880-6-axboe@kernel.dk> Message-ID: <718b4d1fbe9f97592d6d7b76d7a4537d@suse.de> X-Sender: rpenyaev@suse.de User-Agent: Roundcube Webmail Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2019-01-16 18:49, Jens Axboe wrote: [...] > +static int io_allocate_scq_urings(struct io_ring_ctx *ctx, > + struct io_uring_params *p) > +{ > + struct io_sq_ring *sq_ring; > + struct io_cq_ring *cq_ring; > + size_t size; > + int ret; > + > + sq_ring = io_mem_alloc(struct_size(sq_ring, array, p->sq_entries)); It seems that sq_entries, cq_entries are not limited at all. Can nasty app consume a lot of kernel pages calling io_setup_uring() from a loop passing random entries number? (or even better: decreasing entries number, in order to consume all pages orders with min number of loops). -- Roman