From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonas Lahtinen Subject: Re: [PATCH 02/22] drm/i915: introduce simple gemfs Date: Tue, 26 Sep 2017 16:21:47 +0300 Message-ID: <1506432107.5228.26.camel@linux.intel.com> References: <20170925184737.8807-1-matthew.auld@intel.com> <20170925184737.8807-3-matthew.auld@intel.com> <20170926075221.GB32088@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20170926075221.GB32088@kroah.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Greg Kroah-Hartman , Matthew Auld Cc: devel@driverdev.osuosl.org, Dave Hansen , intel-gfx@lists.freedesktop.org, Hugh Dickins , Arve =?ISO-8859-1?Q?Hj=F8nnev=E5g?= , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Riley Andrews , Daniel Vetter , "Kirill A . Shutemov" , Andrew Morton List-Id: dri-devel@lists.freedesktop.org T24gVHVlLCAyMDE3LTA5LTI2IGF0IDA5OjUyICswMjAwLCBHcmVnIEtyb2FoLUhhcnRtYW4gd3Jv dGU6Cj4gT24gTW9uLCBTZXAgMjUsIDIwMTcgYXQgMDc6NDc6MTdQTSArMDEwMCwgTWF0dGhldyBB dWxkIHdyb3RlOgo+ID4gTm90IGEgZnVsbHkgYmxvd24gZ2VtZnMsIGp1c3Qgb3VyIHZlcnkgb3du IHRtcGZzIGtlcm5lbCBtb3VudC4gRG9pbmcgc28KPiA+IG1vdmVzIHVzIGF3YXkgZnJvbSB0aGUg c2htZW1mcyBzaG1fbW50LCBhbmQgZ2l2ZXMgdXMgdGhlIG11Y2ggbmVlZGVkCj4gPiBmbGV4aWJp bGl0eSB0byBkbyB0aGluZ3MgbGlrZSBzZXQgb3VyIG93biBtb3VudCBvcHRpb25zLCBuYW1lbHkg aHVnZT0KPiA+IHdoaWNoIHNob3VsZCBhbGxvdyB1cyB0byBlbmFibGUgdGhlIHVzZSBvZiB0cmFu c3BhcmVudC1odWdlLXBhZ2VzIGZvcgo+ID4gb3VyIHNobWVtIGJhY2tlZCBvYmplY3RzLgo+ID4g Cj4gPiB2MjogdmFyaW91cyBpbXByb3ZlbWVudHMgc3VnZ2VzdGVkIGJ5IEpvb25hcwo+ID4gCj4g PiB2MzogbW92ZSBnZW1mcyBpbnN0YW5jZSB0byBpOTE1Lm1tIGFuZCBzaW1wbGlmeSBub3cgdGhh dCB3ZSBoYXZlCj4gPiBmaWxlX3NldHVwX3dpdGhfbW50Cj4gPiAKPiA+IHY0OiBmYWxsYmFjayB0 byB0bXBmcyBzaG1fbW50IHVwb24gZmFpbHVyZSB0byBzZXR1cCBnZW1mcwo+ID4gCj4gPiB2NTog bWFrZSB0bXBmcyBmYWxsYmFjayBraW5kZXIKPiAKPiBXaHkgZG8gdGhpcyBvbmx5IGZvciBvbmUg c3BlY2lmaWMgZHJpdmVyPyAgU2hvdWxkbid0IHRoZSBkcm0gY29yZSBoYW5kbGUKPiB0aGlzIGZv ciB5b3UsIGZvciBhbGwgb3RoZXIgZHJpdmVycyBhcyB3ZWxsPyAgT3RoZXJ3aXNlIHRyeWluZyB0 byBmaWd1cmUKPiBvdXQgaG93IHRvICJjb250YWluIiB0aGlzIHR5cGUgb2YgdGhpbmcgaXMgZ29p bmcgdG8gYmUgYSBwYWluIChtb3VudAo+IG9wdGlvbnMsIHNlbGludXggb3B0aW9ucywgZXRjLikK CldlIGFjdHVhbGx5IHN0YXJ0ZWQgcXVpdGUgZ3JhbmRlIGJ5IG1ha2luZyBzdHJpcHBlZCBkb3du IHZlcnNpb24gb2YKc2htZW1mcyBmb3IgZHJtIGNvcmUsIGJ1dCBrZXB0IHJ1bm5pbmcgaW50byBu YWNrcyBhYm91dCBob3cgd2Ugd2VyZQppbXBsZW1lbnRpbmcgaXQgKGFmdGVyIGdldHRpbmcgYSBy ZWNvbW1lbmRhdGlvbiB0byB0cnkgaW1wbGVtZW50aW5nIGl0CnNvbWUgd2F5KS4gQWZ0ZXIgYSBm ZXcgaXRlcmF0aW9ucyBhbmQgbWFzc2l2ZSBlbmdpbmVlcmluZyB0aW1lLCB3ZSBoYXZlCmJlZW4g cHJvZ3Jlc3NpdmVseSByZWR1Y2luZyB0aGUgYW1vdW50IG9mIGNoYW5nZXMgb3V0c2lkZSBpOTE1 IGluIHRoZQpob3BlcyB0byBnZXQgdGhpcyBtZXJnZWQuCgpBbmQgYWxsIHRoZSB3aGlsZSBjbG9j ayBpcyB0aWNraW5nLCBzbyB3ZSB0aG91Z2h0IHRoZSBiZXN0IHdheSB0byBnZXQKc29tZXRoaW5n IHRvIHN1cHBvcnQgb3VyIGZ1dHVyZSB3b3JrIGlzIHRvIGltcGxlbWVudCB0aGlzIGZpcnN0IGxv Y2FsbHkKd2l0aCBtaW5pbWFsIGV4dGVybmFsIGNoYW5nZXMgb3V0c2lkZSBpOTE1IGFuZCB0aGVu IG9uY2Ugd2UgaGF2ZQpzb21ldGhpbmcgd29ya2luZywgaXQnbGwgYmUgZWFzaWVyIHRvIGdlbmVy YWxpemUgaXQgZm9yIHRoZSBkcm0gY29yZS4KT3RoZXJ3aXNlIHdlJ2xsIG5ldmVyIGdldCB0byB3 b3JrIHdpdGggdGhlIGh1Z2UgcGFnZSBzdXBwb3J0LCBmb3Igd2hpY2gKZ2VtZnMgaXMgdGhlIHN0 ZXBwaW5nIHN0b25lIGhlcmUuCgpTbyB3ZSdyZSBub3QgcGxhbm5pbmcgb24gc2l0dGluZyBvbiB0 b3Agb2YgaXQsIHdlJ2xsIGp1c3QgaW5jdWJhdGUgaXQKdW5kZXIgaTkxNS8gc28gdGhhdCBpdCds bCB0aGVuIGJlIGxlc3MgcGFpbiBmb3Igb3RoZXJzIHRvIGFkb3B0IHdoZW4KdGhlIGJpZ2dlc3Qg aHVyZGxlcyB3aXRoIGNvcmUgTU0gaW50ZXJhY3Rpb25zIGFyZSBzb3J0ZWQgb3V0LgoKUmVnYXJk cywgSm9vbmFzCi0tIApKb29uYXMgTGFodGluZW4KT3BlbiBTb3VyY2UgVGVjaG5vbG9neSBDZW50 ZXIKSW50ZWwgQ29ycG9yYXRpb24KX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRl c2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8v ZHJpLWRldmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id E4CEA6B0069 for ; Tue, 26 Sep 2017 09:22:07 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id f84so18242462pfj.0 for ; Tue, 26 Sep 2017 06:22:07 -0700 (PDT) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTPS id n73si2143943pfi.98.2017.09.26.06.22.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Sep 2017 06:22:06 -0700 (PDT) Message-ID: <1506432107.5228.26.camel@linux.intel.com> Subject: Re: [PATCH 02/22] drm/i915: introduce simple gemfs From: Joonas Lahtinen Date: Tue, 26 Sep 2017 16:21:47 +0300 In-Reply-To: <20170926075221.GB32088@kroah.com> References: <20170925184737.8807-1-matthew.auld@intel.com> <20170925184737.8807-3-matthew.auld@intel.com> <20170926075221.GB32088@kroah.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Greg Kroah-Hartman , Matthew Auld Cc: intel-gfx@lists.freedesktop.org, devel@driverdev.osuosl.org, linux-mm@kvack.org, Hugh Dickins , Riley Andrews , dri-devel@lists.freedesktop.org, Chris Wilson , Dave Hansen , Arve =?ISO-8859-1?Q?Hj=F8nnev=E5g?= , "Kirill A . Shutemov" , Daniel Vetter , Andrew Morton On Tue, 2017-09-26 at 09:52 +0200, Greg Kroah-Hartman wrote: > On Mon, Sep 25, 2017 at 07:47:17PM +0100, Matthew Auld wrote: > > Not a fully blown gemfs, just our very own tmpfs kernel mount. Doing so > > moves us away from the shmemfs shm_mnt, and gives us the much needed > > flexibility to do things like set our own mount options, namely huge= > > which should allow us to enable the use of transparent-huge-pages for > > our shmem backed objects. > > > > v2: various improvements suggested by Joonas > > > > v3: move gemfs instance to i915.mm and simplify now that we have > > file_setup_with_mnt > > > > v4: fallback to tmpfs shm_mnt upon failure to setup gemfs > > > > v5: make tmpfs fallback kinder > > Why do this only for one specific driver? Shouldn't the drm core handle > this for you, for all other drivers as well? Otherwise trying to figure > out how to "contain" this type of thing is going to be a pain (mount > options, selinux options, etc.) We actually started quite grande by making stripped down version of shmemfs for drm core, but kept running into nacks about how we were implementing it (after getting a recommendation to try implementing it some way). After a few iterations and massive engineering time, we have been progressively reducing the amount of changes outside i915 in the hopes to get this merged. And all the while clock is ticking, so we thought the best way to get something to support our future work is to implement this first locally with minimal external changes outside i915 and then once we have something working, it'll be easier to generalize it for the drm core. Otherwise we'll never get to work with the huge page support, for which gemfs is the stepping stone here. So we're not planning on sitting on top of it, we'll just incubate it under i915/ so that it'll then be less pain for others to adopt when the biggest hurdles with core MM interactions are sorted out. Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org