From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752730AbaHDNew (ORCPT ); Mon, 4 Aug 2014 09:34:52 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:38781 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751972AbaHDNev (ORCPT ); Mon, 4 Aug 2014 09:34:51 -0400 Message-ID: <53DF8BF2.4000309@canonical.com> Date: Mon, 04 Aug 2014 15:34:42 +0200 From: Maarten Lankhorst User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: =?UTF-8?B?Q2hyaXN0aWFuIEvDtm5pZw==?= , airlied@linux.ie CC: thellstrom@vmware.com, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, bskeggs@redhat.com, alexander.deucher@amd.com Subject: Re: [PATCH 09/19] drm/radeon: handle lockup in delayed work, v2 References: <20140731153245.15061.63023.stgit@patser> <20140731153342.15061.54264.stgit@patser> <53DBC1EC.1010001@amd.com> <53DBD269.80807@canonical.com> <53DF462B.2060102@amd.com> <53DF4A7D.3040505@canonical.com> <53DF7516.2010408@amd.com> In-Reply-To: <53DF7516.2010408@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey, op 04-08-14 13:57, Christian König schreef: > Am 04.08.2014 um 10:55 schrieb Maarten Lankhorst: >> op 04-08-14 10:36, Christian König schreef: >>> Hi Maarten, >>> >>> Sorry for the delay. I've got way to much todo recently. >>> >>> Am 01.08.2014 um 19:46 schrieb Maarten Lankhorst: >>>> On 01-08-14 18:35, Christian König wrote: >>>>> Am 31.07.2014 um 17:33 schrieb Maarten Lankhorst: >>>>>> Signed-off-by: Maarten Lankhorst >>>>>> --- >>>>>> V1 had a nasty bug breaking gpu lockup recovery. The fix is not >>>>>> allowing radeon_fence_driver_check_lockup to take exclusive_lock, >>>>>> and kill it during lockup recovery instead. >>>>> That looks like the delayed work starts running as soon as we submit a fence, and not when it's needed for waiting. >>>>> >>>>> Since it's a backup for failing IRQs I would rather put it into radeon_irq_kms.c and start/stop it when the IRQs are started/stoped. >>>> The delayed work is not just for failing irq's, it's also the handler that's used to detect lockups, which is why I trigger after processing fences, and reset the timer after processing. >>> The idea was turning the delayed work on and off when we turn the irq on and off as well, processing of the delayed work handler can still happen in radeon_fence.c >>> >>>> Specifically what happened was this scenario: >>>> >>>> - lock up occurs >>>> - write lock taken by gpu_reset >>>> - delayed work runs, tries to acquire read lock, blocks >>>> - gpu_reset tries to cancel delayed work synchronously >>>> - has to wait for delayed work to finish -> deadlock >>> Why do you want to disable the work item from the lockup handler in the first place? >>> >>> Just take the exclusive lock in the work item, when it concurrently runs with the lockup handler it will just block for the lockup handler to complete. >> With the delayed work radeon_fence_wait no longer handles unreliable interrupts itself, so it has to run from the lockup handler. >> But an alternative solution could be adding a radeon_fence_wait_timeout, ignore the timeout and check if fence is signaled on timeout. >> This would probably be a cleaner solution. > > Yeah, agree. Manually specifying a timeout in the fence wait on lockup handling sounds like the best alternative to me. It'a pain to deal with gpu reset. I've now tried other solutions but that would mean reverting to the old style during gpu lockup recovery, and only running the delayed work when !lockup. But this meant that the timeout was useless to add. I think the cleanest is keeping the v2 patch, because potentially any waiting code can be called during lockup recovery. ~Maarten From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maarten Lankhorst Subject: Re: [PATCH 09/19] drm/radeon: handle lockup in delayed work, v2 Date: Mon, 04 Aug 2014 15:34:42 +0200 Message-ID: <53DF8BF2.4000309@canonical.com> References: <20140731153245.15061.63023.stgit@patser> <20140731153342.15061.54264.stgit@patser> <53DBC1EC.1010001@amd.com> <53DBD269.80807@canonical.com> <53DF462B.2060102@amd.com> <53DF4A7D.3040505@canonical.com> <53DF7516.2010408@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <53DF7516.2010408@amd.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: =?UTF-8?B?Q2hyaXN0aWFuIEvDtm5pZw==?= , airlied@linux.ie Cc: thellstrom@vmware.com, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, bskeggs@redhat.com, alexander.deucher@amd.com List-Id: nouveau.vger.kernel.org SGV5LAoKb3AgMDQtMDgtMTQgMTM6NTcsIENocmlzdGlhbiBLw7ZuaWcgc2NocmVlZjoKPiBBbSAw NC4wOC4yMDE0IHVtIDEwOjU1IHNjaHJpZWIgTWFhcnRlbiBMYW5raG9yc3Q6Cj4+IG9wIDA0LTA4 LTE0IDEwOjM2LCBDaHJpc3RpYW4gS8O2bmlnIHNjaHJlZWY6Cj4+PiBIaSBNYWFydGVuLAo+Pj4K Pj4+IFNvcnJ5IGZvciB0aGUgZGVsYXkuIEkndmUgZ290IHdheSB0byBtdWNoIHRvZG8gcmVjZW50 bHkuCj4+Pgo+Pj4gQW0gMDEuMDguMjAxNCB1bSAxOTo0NiBzY2hyaWViIE1hYXJ0ZW4gTGFua2hv cnN0Ogo+Pj4+IE9uIDAxLTA4LTE0IDE4OjM1LCBDaHJpc3RpYW4gS8O2bmlnIHdyb3RlOgo+Pj4+ PiBBbSAzMS4wNy4yMDE0IHVtIDE3OjMzIHNjaHJpZWIgTWFhcnRlbiBMYW5raG9yc3Q6Cj4+Pj4+ PiBTaWduZWQtb2ZmLWJ5OiBNYWFydGVuIExhbmtob3JzdCA8bWFhcnRlbi5sYW5raG9yc3RAY2Fu b25pY2FsLmNvbT4KPj4+Pj4+IC0tLQo+Pj4+Pj4gVjEgaGFkIGEgbmFzdHkgYnVnIGJyZWFraW5n IGdwdSBsb2NrdXAgcmVjb3ZlcnkuIFRoZSBmaXggaXMgbm90Cj4+Pj4+PiBhbGxvd2luZyByYWRl b25fZmVuY2VfZHJpdmVyX2NoZWNrX2xvY2t1cCB0byB0YWtlIGV4Y2x1c2l2ZV9sb2NrLAo+Pj4+ Pj4gYW5kIGtpbGwgaXQgZHVyaW5nIGxvY2t1cCByZWNvdmVyeSBpbnN0ZWFkLgo+Pj4+PiBUaGF0 IGxvb2tzIGxpa2UgdGhlIGRlbGF5ZWQgd29yayBzdGFydHMgcnVubmluZyBhcyBzb29uIGFzIHdl IHN1Ym1pdCBhIGZlbmNlLCBhbmQgbm90IHdoZW4gaXQncyBuZWVkZWQgZm9yIHdhaXRpbmcuCj4+ Pj4+Cj4+Pj4+IFNpbmNlIGl0J3MgYSBiYWNrdXAgZm9yIGZhaWxpbmcgSVJRcyBJIHdvdWxkIHJh dGhlciBwdXQgaXQgaW50byByYWRlb25faXJxX2ttcy5jIGFuZCBzdGFydC9zdG9wIGl0IHdoZW4g dGhlIElSUXMgYXJlIHN0YXJ0ZWQvc3RvcGVkLgo+Pj4+IFRoZSBkZWxheWVkIHdvcmsgaXMgbm90 IGp1c3QgZm9yIGZhaWxpbmcgaXJxJ3MsIGl0J3MgYWxzbyB0aGUgaGFuZGxlciB0aGF0J3MgdXNl ZCB0byBkZXRlY3QgbG9ja3Vwcywgd2hpY2ggaXMgd2h5IEkgdHJpZ2dlciBhZnRlciBwcm9jZXNz aW5nIGZlbmNlcywgYW5kIHJlc2V0IHRoZSB0aW1lciBhZnRlciBwcm9jZXNzaW5nLgo+Pj4gVGhl IGlkZWEgd2FzIHR1cm5pbmcgdGhlIGRlbGF5ZWQgd29yayBvbiBhbmQgb2ZmIHdoZW4gd2UgdHVy biB0aGUgaXJxIG9uIGFuZCBvZmYgYXMgd2VsbCwgcHJvY2Vzc2luZyBvZiB0aGUgZGVsYXllZCB3 b3JrIGhhbmRsZXIgY2FuIHN0aWxsIGhhcHBlbiBpbiByYWRlb25fZmVuY2UuYwo+Pj4KPj4+PiBT cGVjaWZpY2FsbHkgd2hhdCBoYXBwZW5lZCB3YXMgdGhpcyBzY2VuYXJpbzoKPj4+Pgo+Pj4+IC0g bG9jayB1cCBvY2N1cnMKPj4+PiAtIHdyaXRlIGxvY2sgdGFrZW4gYnkgZ3B1X3Jlc2V0Cj4+Pj4g LSBkZWxheWVkIHdvcmsgcnVucywgdHJpZXMgdG8gYWNxdWlyZSByZWFkIGxvY2ssIGJsb2Nrcwo+ Pj4+IC0gZ3B1X3Jlc2V0IHRyaWVzIHRvIGNhbmNlbCBkZWxheWVkIHdvcmsgc3luY2hyb25vdXNs eQo+Pj4+IC0gaGFzIHRvIHdhaXQgZm9yIGRlbGF5ZWQgd29yayB0byBmaW5pc2ggLT4gZGVhZGxv Y2sKPj4+IFdoeSBkbyB5b3Ugd2FudCB0byBkaXNhYmxlIHRoZSB3b3JrIGl0ZW0gZnJvbSB0aGUg bG9ja3VwIGhhbmRsZXIgaW4gdGhlIGZpcnN0IHBsYWNlPwo+Pj4KPj4+IEp1c3QgdGFrZSB0aGUg ZXhjbHVzaXZlIGxvY2sgaW4gdGhlIHdvcmsgaXRlbSwgd2hlbiBpdCBjb25jdXJyZW50bHkgcnVu cyB3aXRoIHRoZSBsb2NrdXAgaGFuZGxlciBpdCB3aWxsIGp1c3QgYmxvY2sgZm9yIHRoZSBsb2Nr dXAgaGFuZGxlciB0byBjb21wbGV0ZS4KPj4gV2l0aCB0aGUgZGVsYXllZCB3b3JrIHJhZGVvbl9m ZW5jZV93YWl0IG5vIGxvbmdlciBoYW5kbGVzIHVucmVsaWFibGUgaW50ZXJydXB0cyBpdHNlbGYs IHNvIGl0IGhhcyB0byBydW4gZnJvbSB0aGUgbG9ja3VwIGhhbmRsZXIuCj4+IEJ1dCBhbiBhbHRl cm5hdGl2ZSBzb2x1dGlvbiBjb3VsZCBiZSBhZGRpbmcgYSByYWRlb25fZmVuY2Vfd2FpdF90aW1l b3V0LCBpZ25vcmUgdGhlIHRpbWVvdXQgYW5kIGNoZWNrIGlmIGZlbmNlIGlzIHNpZ25hbGVkIG9u IHRpbWVvdXQuCj4+IFRoaXMgd291bGQgcHJvYmFibHkgYmUgYSBjbGVhbmVyIHNvbHV0aW9uLgo+ Cj4gWWVhaCwgYWdyZWUuIE1hbnVhbGx5IHNwZWNpZnlpbmcgYSB0aW1lb3V0IGluIHRoZSBmZW5j ZSB3YWl0IG9uIGxvY2t1cCBoYW5kbGluZyBzb3VuZHMgbGlrZSB0aGUgYmVzdCBhbHRlcm5hdGl2 ZSB0byBtZS4KSXQnYSBwYWluIHRvIGRlYWwgd2l0aCBncHUgcmVzZXQuCgpJJ3ZlIG5vdyB0cmll ZCBvdGhlciBzb2x1dGlvbnMgYnV0IHRoYXQgd291bGQgbWVhbiByZXZlcnRpbmcgdG8gdGhlIG9s ZCBzdHlsZSBkdXJpbmcgZ3B1IGxvY2t1cCByZWNvdmVyeSwgYW5kIG9ubHkgcnVubmluZyB0aGUg ZGVsYXllZCB3b3JrIHdoZW4gIWxvY2t1cC4KQnV0IHRoaXMgbWVhbnQgdGhhdCB0aGUgdGltZW91 dCB3YXMgdXNlbGVzcyB0byBhZGQuIEkgdGhpbmsgdGhlIGNsZWFuZXN0IGlzIGtlZXBpbmcgdGhl IHYyIHBhdGNoLCBiZWNhdXNlIHBvdGVudGlhbGx5IGFueSB3YWl0aW5nIGNvZGUgY2FuIGJlIGNh bGxlZCBkdXJpbmcgbG9ja3VwIHJlY292ZXJ5LgoKfk1hYXJ0ZW4KCl9fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJp LWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3Jn L21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg==