From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: Re: [PATCH 02/22] drm/i915: introduce simple gemfs Date: Tue, 26 Sep 2017 23:34:40 +0200 Message-ID: <20170926213440.GD3418@kroah.com> References: <20170925184737.8807-1-matthew.auld@intel.com> <20170925184737.8807-3-matthew.auld@intel.com> <20170926075221.GB32088@kroah.com> <1506432107.5228.26.camel@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <1506432107.5228.26.camel@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Joonas Lahtinen Cc: devel@driverdev.osuosl.org, linux-mm@kvack.org, intel-gfx@lists.freedesktop.org, Hugh Dickins , Riley Andrews , dri-devel@lists.freedesktop.org, Dave Hansen , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Matthew Auld , "Kirill A . Shutemov" , Daniel Vetter , Andrew Morton List-Id: dri-devel@lists.freedesktop.org T24gVHVlLCBTZXAgMjYsIDIwMTcgYXQgMDQ6MjE6NDdQTSArMDMwMCwgSm9vbmFzIExhaHRpbmVu IHdyb3RlOgo+IE9uIFR1ZSwgMjAxNy0wOS0yNiBhdCAwOTo1MiArMDIwMCwgR3JlZyBLcm9haC1I YXJ0bWFuIHdyb3RlOgo+ID4gT24gTW9uLCBTZXAgMjUsIDIwMTcgYXQgMDc6NDc6MTdQTSArMDEw MCwgTWF0dGhldyBBdWxkIHdyb3RlOgo+ID4gPiBOb3QgYSBmdWxseSBibG93biBnZW1mcywganVz dCBvdXIgdmVyeSBvd24gdG1wZnMga2VybmVsIG1vdW50LiBEb2luZyBzbwo+ID4gPiBtb3ZlcyB1 cyBhd2F5IGZyb20gdGhlIHNobWVtZnMgc2htX21udCwgYW5kIGdpdmVzIHVzIHRoZSBtdWNoIG5l ZWRlZAo+ID4gPiBmbGV4aWJpbGl0eSB0byBkbyB0aGluZ3MgbGlrZSBzZXQgb3VyIG93biBtb3Vu dCBvcHRpb25zLCBuYW1lbHkgaHVnZT0KPiA+ID4gd2hpY2ggc2hvdWxkIGFsbG93IHVzIHRvIGVu YWJsZSB0aGUgdXNlIG9mIHRyYW5zcGFyZW50LWh1Z2UtcGFnZXMgZm9yCj4gPiA+IG91ciBzaG1l bSBiYWNrZWQgb2JqZWN0cy4KPiA+ID4gCj4gPiA+IHYyOiB2YXJpb3VzIGltcHJvdmVtZW50cyBz dWdnZXN0ZWQgYnkgSm9vbmFzCj4gPiA+IAo+ID4gPiB2MzogbW92ZSBnZW1mcyBpbnN0YW5jZSB0 byBpOTE1Lm1tIGFuZCBzaW1wbGlmeSBub3cgdGhhdCB3ZSBoYXZlCj4gPiA+IGZpbGVfc2V0dXBf d2l0aF9tbnQKPiA+ID4gCj4gPiA+IHY0OiBmYWxsYmFjayB0byB0bXBmcyBzaG1fbW50IHVwb24g ZmFpbHVyZSB0byBzZXR1cCBnZW1mcwo+ID4gPiAKPiA+ID4gdjU6IG1ha2UgdG1wZnMgZmFsbGJh Y2sga2luZGVyCj4gPiAKPiA+IFdoeSBkbyB0aGlzIG9ubHkgZm9yIG9uZSBzcGVjaWZpYyBkcml2 ZXI/ICBTaG91bGRuJ3QgdGhlIGRybSBjb3JlIGhhbmRsZQo+ID4gdGhpcyBmb3IgeW91LCBmb3Ig YWxsIG90aGVyIGRyaXZlcnMgYXMgd2VsbD8gIE90aGVyd2lzZSB0cnlpbmcgdG8gZmlndXJlCj4g PiBvdXQgaG93IHRvICJjb250YWluIiB0aGlzIHR5cGUgb2YgdGhpbmcgaXMgZ29pbmcgdG8gYmUg YSBwYWluIChtb3VudAo+ID4gb3B0aW9ucywgc2VsaW51eCBvcHRpb25zLCBldGMuKQo+IAo+IFdl IGFjdHVhbGx5IHN0YXJ0ZWQgcXVpdGUgZ3JhbmRlIGJ5IG1ha2luZyBzdHJpcHBlZCBkb3duIHZl cnNpb24gb2YKPiBzaG1lbWZzIGZvciBkcm0gY29yZSwgYnV0IGtlcHQgcnVubmluZyBpbnRvIG5h Y2tzIGFib3V0IGhvdyB3ZSB3ZXJlCj4gaW1wbGVtZW50aW5nIGl0IChhZnRlciBnZXR0aW5nIGEg cmVjb21tZW5kYXRpb24gdG8gdHJ5IGltcGxlbWVudGluZyBpdAo+IHNvbWUgd2F5KS4gQWZ0ZXIg YSBmZXcgaXRlcmF0aW9ucyBhbmQgbWFzc2l2ZSBlbmdpbmVlcmluZyB0aW1lLCB3ZSBoYXZlCj4g YmVlbiBwcm9ncmVzc2l2ZWx5IHJlZHVjaW5nIHRoZSBhbW91bnQgb2YgY2hhbmdlcyBvdXRzaWRl IGk5MTUgaW4gdGhlCj4gaG9wZXMgdG8gZ2V0IHRoaXMgbWVyZ2VkLgo+IAo+IEFuZCBhbGwgdGhl IHdoaWxlIGNsb2NrIGlzIHRpY2tpbmcsIHNvIHdlIHRob3VnaHQgdGhlIGJlc3Qgd2F5IHRvIGdl dAo+IHNvbWV0aGluZyB0byBzdXBwb3J0IG91ciBmdXR1cmUgd29yayBpcyB0byBpbXBsZW1lbnQg dGhpcyBmaXJzdCBsb2NhbGx5Cj4gd2l0aCBtaW5pbWFsIGV4dGVybmFsIGNoYW5nZXMgb3V0c2lk ZSBpOTE1IGFuZCB0aGVuIG9uY2Ugd2UgaGF2ZQo+IHNvbWV0aGluZyB3b3JraW5nLCBpdCdsbCBi ZSBlYXNpZXIgdG8gZ2VuZXJhbGl6ZSBpdCBmb3IgdGhlIGRybSBjb3JlLgo+IE90aGVyd2lzZSB3 ZSdsbCBuZXZlciBnZXQgdG8gd29yayB3aXRoIHRoZSBodWdlIHBhZ2Ugc3VwcG9ydCwgZm9yIHdo aWNoCj4gZ2VtZnMgaXMgdGhlIHN0ZXBwaW5nIHN0b25lIGhlcmUuCj4gCj4gU28gd2UncmUgbm90 IHBsYW5uaW5nIG9uIHNpdHRpbmcgb24gdG9wIG9mIGl0LCB3ZSdsbCBqdXN0IGluY3ViYXRlIGl0 Cj4gdW5kZXIgaTkxNS8gc28gdGhhdCBpdCdsbCB0aGVuIGJlIGxlc3MgcGFpbiBmb3Igb3RoZXJz IHRvIGFkb3B0IHdoZW4KPiB0aGUgYmlnZ2VzdCBodXJkbGVzIHdpdGggY29yZSBNTSBpbnRlcmFj dGlvbnMgYXJlIHNvcnRlZCBvdXQuCgpCdXQgYnkgZG9pbmcgdGhpcywgeW91IGFyZSBub3cgY3Jl YXRpbmcgYSBuZXcgdXNlci9rZXJuZWwgYXBpIHRoYXQgeW91CmhhdmUgdG8gc3VwcG9ydCBmb3Ig Zm9yZXZlciwgcmlnaHQ/ICBXaWxsIGl0IG5vdCBjaGFuZ2UgaWYgeW91IG1ha2UgaXQKImdlbmVy aWMiIHRvIHRoZSBkcm0gY29yZSBldmVudHVhbGx5PwoKV29yc2UgY2FzZSwgbmFtZSBpdCBhIGdl bmVyaWMgbmFtZSB0aGF0IGV2ZXJ5b25lIHdpbGwgZW5kIHVwIHVzaW5nIGluCnRoZSBmdXR1cmUs IGFuZCB0aGVuIHlvdSBjYW4ganVzdCBjbGFpbSB0aGF0IGFsbCBvdGhlciBkcml2ZXJzIG5lZWQg dG8KaW1wbGVtZW50IGl0IDopCgp0aGFua3MsCgpncmVnIGstaApfX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1k ZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcv bWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id CD45E6B0069 for ; Tue, 26 Sep 2017 17:34:33 -0400 (EDT) Received: by mail-wr0-f197.google.com with SMTP id r74so2074578wrb.7 for ; Tue, 26 Sep 2017 14:34:33 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id t50si7968918wrc.507.2017.09.26.14.34.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Sep 2017 14:34:32 -0700 (PDT) Date: Tue, 26 Sep 2017 23:34:40 +0200 From: Greg Kroah-Hartman Subject: Re: [PATCH 02/22] drm/i915: introduce simple gemfs Message-ID: <20170926213440.GD3418@kroah.com> References: <20170925184737.8807-1-matthew.auld@intel.com> <20170925184737.8807-3-matthew.auld@intel.com> <20170926075221.GB32088@kroah.com> <1506432107.5228.26.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1506432107.5228.26.camel@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Joonas Lahtinen Cc: Matthew Auld , devel@driverdev.osuosl.org, Dave Hansen , intel-gfx@lists.freedesktop.org, Hugh Dickins , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , dri-devel@lists.freedesktop.org, Chris Wilson , linux-mm@kvack.org, Riley Andrews , Daniel Vetter , "Kirill A . Shutemov" , Andrew Morton On Tue, Sep 26, 2017 at 04:21:47PM +0300, Joonas Lahtinen wrote: > 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. But by doing this, you are now creating a new user/kernel api that you have to support for forever, right? Will it not change if you make it "generic" to the drm core eventually? Worse case, name it a generic name that everyone will end up using in the future, and then you can just claim that all other drivers need to implement it :) thanks, greg k-h -- 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