From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-130196-1518017583-2-4233078917693674023 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 0.001, RCVD_IN_DNSWL_MED -2.3, SPF_PASS -0.001, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='140.211.166.133', Host='smtp2.osuosl.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: driverdev-devel-bounces@linuxdriverproject.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518017583; b=Ncm5v9HXGKgMV5U5IYMCKpWTL/SfmY3roFraMc1/jZ4S6N+ YnSlbYjPT6PXsi6qfmsQf0cUlHs1kfvdyFvQHc3u03z6LAsZTEJhgrvrlVGdwMig Ysd5cX688nX18nNO6D5Ib2hTxQe+p2T4ZE4Y8Fqkf5Dvh357Xy3PYeEeOdMWQtXX 67sQYiu4OUvX85aQopWVz8Dz1iQnv/Juy522sNxqOf/kKG+V7BTwUVpOuakSyWR8 FiK5zaGN0WfdssazKVgafQyalGeXy9BE8ycg8swGyWvDWGL9ZFdN3ncQ/FxT1UU6 q9BvKjfbg/z01wqGUd+GBFkGKy6YCggfyfyR+Nw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=subject:to:references:from:message-id :date:mime-version:in-reply-to:list-id:list-unsubscribe :list-archive:list-post:list-help:list-subscribe:cc :content-transfer-encoding:content-type:sender; s=arctest; t= 1518017583; bh=WLGlHLrPpFPFP41kdQJDuQOr+Vhq9i6eqypz4GNCPns=; b=p wbOre3vvtTRfw+fevHGF1JMSreLEU2F0AgxloRH3z7aO7KyQYNqk9KuGD4aMTUKc 0myfZ39J8P9F6r+TOr2xP94CJGEQBggepcP7WlIKrRYcjI/8x3a8EEusxWgmotwp tCzOZMwHqsyzACuD8HqjhUq1XYhwjXKXfiClhaTMUlX06VtwpLplSJ8uEDCWC8lj WmEvmILq+TtpV5H9yHs0h9USl4XoZ9hknBOpXat9anLOlWpCbzPS5n2XBV5qnPAp kJANdF+Sl09U0SQqZyjtakGe327nQvCDL/6fwrE7XHtjcNGoFp1TteP2PCHgokM+ tk02CxsMaDQTxToU7wX1Q== ARC-Authentication-Results: i=1; mx4.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=140.211.166.133 (smtp2.osuosl.org); spf=pass smtp.mailfrom=driverdev-devel-bounces@linuxdriverproject.org smtp.helo=hemlock.osuosl.org; x-aligned-from=fail; x-google-dkim=fail (body has been altered; 2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=OD00Pd9q; x-ptr=fail x-ptr-helo=hemlock.osuosl.org x-ptr-lookup=smtp2.osuosl.org; x-return-mx=pass smtp.domain=linuxdriverproject.org smtp.result=pass smtp_is_org_domain=yes header.domain=redhat.com header.result=pass header_is_org_domain=yes; x-tls=pass version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128 Authentication-Results: mx4.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=140.211.166.133 (smtp2.osuosl.org); spf=pass smtp.mailfrom=driverdev-devel-bounces@linuxdriverproject.org smtp.helo=hemlock.osuosl.org; x-aligned-from=fail; x-google-dkim=fail (body has been altered; 2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=OD00Pd9q; x-ptr=fail x-ptr-helo=hemlock.osuosl.org x-ptr-lookup=smtp2.osuosl.org; x-return-mx=pass smtp.domain=linuxdriverproject.org smtp.result=pass smtp_is_org_domain=yes header.domain=redhat.com header.result=pass header_is_org_domain=yes; x-tls=pass version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128 X-Remote-Delivered-To: driverdev-devel@osuosl.org X-Google-Smtp-Source: AH8x227VUOomzqAONj+MOFmMyXa0vqGeytnXgHgfmlGxjGvFBAY5hDhd3sTY0eU0m1HZy1YZ/jGjoA== Subject: Re: staging: ion: ION allocation fall back order depends on heap linkage order To: Alexey Skidanov , devel@driverdev.osuosl.org References: <58951af2-a84e-7d7c-e956-ece3190aa8c2@redhat.com> <0217ee91-25fa-f563-81bd-ba4ad4dc9377@intel.com> <3f77b591-6248-da0a-e20d-88ca26a60a95@intel.com> From: Laura Abbott Message-ID: <9aab5e55-a2f1-b05d-3568-0a4491ff51f1@redhat.com> Date: Wed, 7 Feb 2018 07:32:53 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <3f77b591-6248-da0a-e20d-88ca26a60a95@intel.com> Content-Language: en-US X-BeenThere: driverdev-devel@linuxdriverproject.org X-Mailman-Version: 2.1.24 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 02/07/2018 07:10 AM, Alexey Skidanov wrote: > > > On 02/07/2018 04:58 PM, Laura Abbott wrote: >> On 02/06/2018 11:05 PM, Alexey Skidanov wrote: >>> >>> >>>> Yup, you've hit upon a key problem. Having fallbacks be stable >>>> was always a problem and the recommendation these days is to >>>> not rely on them. You can specify a heap at a time and fallback >>>> manually if you want that behavior. >>>> >>>> If you have a proposal to make fallbacks work reliably without >>>> overly complicating the ABI I'm happy to review it. >>>> >>>> Thanks, >>>> Laura >>>> >>> I think it's possible to "automate" the "manual fallback" behavior. But >>> the real issues is using heap id to specify the particular heap object. >>> >>> Current API (allocation IOCTL) requires to specify the particular heap >>> object by using heap id. From the other hand, the user space doesn't >>> control the heaps creation order and heap id assignment. So it may be >>> tricky, especially when more than one object of the same heap type is >>> created automatically. >>> >>> Thanks, >>> Alexey >>> >>> >> >> The query ioctl is designed to get the heap ID information without >> needing to rely on the linking order or anything else defined in >> the kernel. >> >> Thanks, >> Laura > > That is true. But if we have 2 *automatically created* heaps of the same > type, how userspace can distinguish between them? > > Thanks, > Alexey > The query ioctl also gives the name which should be different for each heap. It's not ideal but the name/heap type are the best way to differentiate between heaps without resorting to hard coding. Thanks, Laura _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel