From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-29863-1518016226-2-14515886033810946648 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no 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-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=1518016224; b=ugtQoUkHEFWvjRznD6NAEcOIGcl4Du+P4JQ+4FMPeVP5YfH rU23bFFcn6KXNSp9v7NJIP8f6HQRRHnP9tOnV6JGLEy09RAQgDgHNLlMy7r12Z1p k9Ud3hXQCEbXJAGA5zUjD6w7PlVk/aRegUAkX4iIUMKGuo7+flhAD/e+CEPDMzTi 611U08taKXo2akCkSdehuMFhtreAy9GNlREXgx7bNEibDwA6nYi2S55WsBoN+9wk c4qp68Etvt8/5sdWvSB3FxwvH8kCgEah0eZCGLyOMvJindv/ztdDpuN9l6oq5cFt BnbnpWbpMoLj7E51C6wgzrKVRe+rcSxOLkN7cIA== 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-type :content-transfer-encoding:sender; s=arctest; t=1518016224; bh=U JwAl24x14loUpzLRFXGVH8+3dyjff7wsMauMtBphpY=; b=GGxlOPqbnBWa6yKei gBPd38phOmL+3D/iEW7CmmPW3dCmJ4p4syRtfRg8+HIT/8QE/9uM0dgD2uPCUeYY GH4Hxc2AGz9ASVIbuLdVOfZ2miAXZhLckOnW2NkBzT3vAELBxK8uXG5pi96w1OD9 pUtSlTtxY/v0CUBdjQQOzr/1eejcIFImP1MGnbJFnWKxs+vUd3abjJPGM5Yjicl0 d8g8016ACmHhY1owMH8Th9DWciTaw6Dirb6PiBxYGOLV79cUMOU9jztSWnU8dk2O KvkGo+o0qbHvHl+1lrbwIwCGOxLij19hGzFOyLlj2wQVhrCP3e5hEeNTl4WxLB6d d2wlg== ARC-Authentication-Results: i=1; mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=intel.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-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=intel.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: mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=intel.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-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=intel.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-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,473,1511856000"; d="scan'208";a="199401662" Subject: Re: staging: ion: ION allocation fall back order depends on heap linkage order To: Laura Abbott , devel@driverdev.osuosl.org References: <58951af2-a84e-7d7c-e956-ece3190aa8c2@redhat.com> <0217ee91-25fa-f563-81bd-ba4ad4dc9377@intel.com> From: Alexey Skidanov Message-ID: <3f77b591-6248-da0a-e20d-88ca26a60a95@intel.com> Date: Wed, 7 Feb 2018 17:10:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 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 _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel