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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 362B0C43387 for ; Thu, 17 Jan 2019 20:09:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 004B52087E for ; Thu, 17 Jan 2019 20:09:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="pxf6lzfd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729385AbfAQUJK (ORCPT ); Thu, 17 Jan 2019 15:09:10 -0500 Received: from mail-io1-f65.google.com ([209.85.166.65]:44305 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729344AbfAQUJJ (ORCPT ); Thu, 17 Jan 2019 15:09:09 -0500 Received: by mail-io1-f65.google.com with SMTP id r200so8825860iod.11 for ; Thu, 17 Jan 2019 12:09:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=bvxVNUAYWyLoUyeunpdxw6P0oEtJCoMzB0zB+HG7fAY=; b=pxf6lzfd87yR3ogkhI/R1LD6BBG9WkwYPO9N4xnD0+4NCAgI0xrr+v+0R8LOCpEwKO 6TfvYDAlKffO5RgSUvCT82f0gc8H6aE1Tyex1RU1UZJ6pwTdRYumcmzDqHS/CKKNStfC XFz7fHbp3GmP3ZqOBv4oYWMTZ7ivnGgPoSZfYLwk7WagQr0k2xTOsACgw+XUtMBrdwBg wS+KSGFPPt9ULKg+DvjoqNTqIOnpZLRyOoTj6dQ3VYvE95Amv5WAPuJsWmX4HEOeK+bJ +DUrJz7ylDFyzwTsbnqXCnoj5Hmo753/Os2Gq8s4EvVV82gXFz7rvbKwGeXSlX68glgx tlrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=bvxVNUAYWyLoUyeunpdxw6P0oEtJCoMzB0zB+HG7fAY=; b=YfvAnhOG836hC3RPoSRD59UeI/QZ4L8NJ4qjcdKgHJHmZowXnDnHnN3LqGaNA6YXu4 7E/K+j+Gls47xjb29X5JjcN5MA57ygXTsquVU4V6C9P1btexaIP7UJDaAKYZQPPrjof9 Cia3or3vEgE8PCC6jveddjeR3wZBHVwd3feKeBdOcVba/TUjrvnQoUJxQbCPVmSKnzm0 2PEVkZNagKAlkos1Qctx2k0MkUWPQ+cS/MkwRgEUwOle8CVYcV7FTGtdgMdxVnWXvB8o YAU/GF24s3oAEvMsqhGOkOZxgJdPhcSNGWFmRI6UQrXb7NNdGUNLbjlHgdGMoqSQnv2P 3cBw== X-Gm-Message-State: AJcUukcikyePRtdP5KLGXviUS8URZiSj/dJQRy7h4BEErFB3kleVf7AF /bpaYFfNmxnH3jcZ68TfORUKpg== X-Google-Smtp-Source: ALg8bN57eBZD6lbL4f35ZAHXCME4dh8TMMf6EB/H3JpRiA+bpKqmGyaUBQDZnnl54n5Xu1gQeYqiPA== X-Received: by 2002:a6b:ca04:: with SMTP id a4mr9190922iog.254.1547755748598; Thu, 17 Jan 2019 12:09:08 -0800 (PST) Received: from [192.168.1.56] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id i201sm953899ioa.1.2019.01.17.12.09.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 17 Jan 2019 12:09:07 -0800 (PST) Subject: Re: [PATCH 05/15] Add io_uring IO interface To: Jeff Moyer Cc: Roman Penyaev , linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-block@vger.kernel.org, linux-arch@vger.kernel.org, hch@lst.de, avi@scylladb.com, linux-block-owner@vger.kernel.org References: <20190116175003.17880-1-axboe@kernel.dk> <20190116175003.17880-6-axboe@kernel.dk> <718b4d1fbe9f97592d6d7b76d7a4537d@suse.de> From: Jens Axboe Message-ID: Date: Thu, 17 Jan 2019 13:09:06 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 1/17/19 1:03 PM, Jeff Moyer wrote: > Jens Axboe writes: > >> On 1/17/19 5:48 AM, Roman Penyaev wrote: >>> 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). >> >> Yes, that's an oversight, we should have a limit in place. I'll add that. > > Can we charge the ring memory to the RLIMIT_MEMLOCK as well? I'd prefer > not to repeat the mistake of fs.aio-max-nr. Sure, we can do that. With the ring limited in size (it's now 4k entries at most), the amount of memory gobbled up by that is much smaller than the fixed buffers. A max sized ring is about 256k of memory. -- Jens Axboe