Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752773AbaK0Idu (ORCPT ); Thu, 27 Nov 2014 03:33:50 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42888 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750922AbaK0Ids (ORCPT ); Thu, 27 Nov 2014 03:33:48 -0500 Message-ID: <5476E1E7.1030402@canonical.com> Date: Thu, 27 Nov 2014 09:33:43 +0100 From: Maarten Lankhorst User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Tobias Klausmann , Michael Marineau CC: David Airlie , linux-kernel@vger.kernel.org, Ben Skeggs , dri-devel@lists.freedesktop.org Subject: Re: 3.18-rc regression: drm/nouveau: use shared fences for readable objects References: <546C5085.1020300@canonical.com> <546DAC16.80704@canonical.com> <5470C02F.6080103@canonical.com> <54743306.8080907@canonical.com> <54767BE7.8020401@mni.thm.de> In-Reply-To: <54767BE7.8020401@mni.thm.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey, Op 27-11-14 om 02:18 schreef Tobias Klausmann: > > > On 26.11.2014 21:29, Michael Marineau wrote: >> On Mon, Nov 24, 2014 at 11:43 PM, Maarten Lankhorst >> wrote: >>> Hey, >>> >>> Op 22-11-14 om 21:16 schreef Michael Marineau: >>>> On Nov 22, 2014 11:45 AM, "Michael Marineau" wrote: >>>>> On Nov 22, 2014 8:56 AM, "Maarten Lankhorst" < >>>> maarten.lankhorst@canonical.com> wrote: >>>>>> Hey, >>>>>> >>>>>> Op 22-11-14 om 01:19 schreef Michael Marineau: >>>>>>> On Thu, Nov 20, 2014 at 12:53 AM, Maarten Lankhorst >>>>>>> wrote: >>>>>>>> Op 20-11-14 om 05:06 schreef Michael Marineau: >>>>>>>>> On Wed, Nov 19, 2014 at 12:10 AM, Maarten Lankhorst >>>>>>>>> wrote: >>>>>>>>>> Hey, >>>>>>>>>> >>>>>>>>>> On 19-11-14 07:43, Michael Marineau wrote: >>>>>>>>>>> On 3.18-rc kernel's I have been intermittently experiencing GPU >>>>>>>>>>> lockups shortly after startup, accompanied with one or both of the >>>>>>>>>>> following errors: >>>>>>>>>>> >>>>>>>>>>> nouveau E[ PFIFO][0000:01:00.0] read fault at 0x000734a000 [PTE] >>>>>>>>>>> from PBDMA0/HOST_CPU on channel 0x007faa3000 [unknown] >>>>>>>>>>> nouveau E[ DRM] GPU lockup - switching to software fbcon >>>>>>>>>>> >>>>>>>>>>> I was able to trace the issue with bisect to commit >>>>>>>>>>> 809e9447b92ffe1346b2d6ec390e212d5307f61c "drm/nouveau: use shared >>>>>>>>>>> fences for readable objects". The lockups appear to have cleared >>>> up >>>>>>>>>>> since reverting that and a few related followup commits: >>>>>>>>>>> >>>>>>>>>>> 809e9447: "drm/nouveau: use shared fences for readable objects" >>>>>>>>>>> 055dffdf: "drm/nouveau: bump driver patchlevel to 1.2.1" >>>>>>>>>>> e3be4c23: "drm/nouveau: specify if interruptible wait is desired >>>> in >>>>>>>>>>> nouveau_fence_sync" >>>>>>>>>>> 15a996bb: "drm/nouveau: assign fence_chan->name correctly" >>>>>>>>>> Weird. I'm not sure yet what causes it. >>>>>>>>>> >>>>>>>>>> >>>> http://cgit.freedesktop.org/~mlankhorst/linux/commit/?h=fixed-fences-for-bisect&id=86be4f216bbb9ea3339843a5658d4c21162c7ee2 >>>>>>>>> Building a kernel from that commit gives me an entirely new >>>> behavior: >>>>>>>>> X hangs for at least 10-20 seconds at a time with brief moments of >>>>>>>>> responsiveness before hanging again while gitk on the kernel repo >>>>>>>>> loads. Otherwise the system is responsive. The head of that >>>>>>>>> fixed-fences-for-bisect branch (1c6aafb5) which is the "use shared >>>>>>>>> fences for readable objects" commit I originally bisected to does >>>>>>>>> feature the complete lockups I was seeing before. >>>>>>>> Ok for the sake of argument lets just assume they're separate bugs, >>>> and we should look at xorg >>>>>>>> hanging first. >>>>>>>> >>>>>>>> Is there anything in the dmesg when the hanging happens? >>>>>>>> >>>>>>>> And it's probably 15 seconds, if it's called through >>>> nouveau_fence_wait. >>>>>>>> Try changing else if (!ret) to else if (WARN_ON(!ret)) in that >>>> function, and see if you get some dmesg spam. :) >>>>>>> Adding the WARN_ON to 86be4f21 repots the following: >>>>>>> >>>>>>> [ 1188.676073] ------------[ cut here ]------------ >>>>>>> [ 1188.676161] WARNING: CPU: 1 PID: 474 at >>>>>>> drivers/gpu/drm/nouveau/nouveau_fence.c:359 >>>>>>> nouveau_fence_wait.part.9+0x33/0x40 [nouveau]() >>>>>>> [ 1188.676166] Modules linked in: rndis_host cdc_ether usbnet mii bnep >>>>>>> ecb btusb bluetooth rfkill bridge stp llc hid_generic usb_storage >>>>>>> joydev mousedev hid_apple usbhid bcm5974 nls_iso8859_1 nls_cp437 vfat >>>>>>> fat nouveau snd_hda_codec_hdmi coretemp x86_pkg_temp_thermal >>>>>>> intel_powerclamp kvm_intel kvm iTCO_wdt crct10dif_pclmul >>>>>>> iTCO_vendor_support crc32c_intel evdev aesni_intel mac_hid aes_x86_64 >>>>>>> lrw glue_helper ablk_helper applesmc snd_hda_codec_cirrus cryptd >>>>>>> input_polldev snd_hda_codec_generic mxm_wmi led_class wmi microcode >>>>>>> hwmon snd_hda_intel ttm snd_hda_controller lpc_ich i2c_i801 mfd_core >>>>>>> snd_hda_codec i2c_algo_bit snd_hwdep drm_kms_helper snd_pcm sbs drm >>>>>>> apple_gmux i2ccore snd_timer snd agpgart mei_me soundcore sbshc mei >>>>>>> video xhci_hcd usbcore usb_common apple_bl button battery ac efivars >>>>>>> autofs4 >>>>>>> [ 1188.676300] efivarfs >>>>>>> [ 1188.676308] CPU: 1 PID: 474 Comm: Xorg Tainted: G W >>>>>>> 3.17.0-rc2-nvtest+ #147 >>>>>>> [ 1188.676313] Hardware name: Apple Inc. >>>>>>> MacBookPro11,3/Mac-2BD1B31983FE1663, BIOS >>>>>>> MBP112.88Z.0138.B11.1408291503 08/29/2014 >>>>>>> [ 1188.676316] 0000000000000009 ffff88045daebce8 ffffffff814f0c09 >>>>>>> 0000000000000000 >>>>>>> [ 1188.676325] ffff88045daebd20 ffffffff8104ea5d ffff88006a6c1468 >>>>>>> 00000000fffffff0 >>>>>>> [ 1188.676333] 0000000000000000 0000000000000000 ffff88006a6c1000 >>>>>>> ffff88045daebd30 >>>>>>> [ 1188.676341] Call Trace: >>>>>>> [ 1188.676356] [] dump_stack+0x4d/0x66 >>>>>>> [ 1188.676369] [] warn_slowpath_common+0x7d/0xa0 >>>>>>> [ 1188.676377] [] warn_slowpath_null+0x1a/0x20 >>>>>>> [ 1188.676439] [] >>>>>>> nouveau_fence_wait.part.9+0x33/0x40 [nouveau] >>>>>>> [ 1188.676496] [] nouveau_fence_wait+0x16/0x30 >>>> [nouveau] >>>>>>> [ 1188.676552] [] >>>>>>> nouveau_gem_ioctl_cpu_prep+0xef/0x1f0 [nouveau] >>>>>>> [ 1188.676578] [] drm_ioctl+0x1ec/0x660 [drm] >>>>>>> [ 1188.676590] [] ? >>>> _raw_spin_unlock_irqrestore+0x36/0x70 >>>>>>> [ 1188.676600] [] ? trace_hardirqs_on+0xd/0x10 >>>>>>> [ 1188.676655] [] nouveau_drm_ioctl+0x54/0xc0 >>>> [nouveau] >>>>>>> [ 1188.676663] [] do_vfs_ioctl+0x300/0x520 >>>>>>> [ 1188.676671] [] ? sysret_check+0x22/0x5d >>>>>>> [ 1188.676677] [] SyS_ioctl+0x41/0x80 >>>>>>> [ 1188.676683] [] system_call_fastpath+0x16/0x1b >>>>>>> [ 1188.676688] ---[ end trace 6f7a510865b4674f ]--- >>>>>>> >>>>>>> Here are the fence events that fired during that particular >>>> fence_wait: >>>>>>> Xorg 474 [004] 1173.667645: fence:fence_wait_start: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56910 >>>>>>> Xorg 474 [004] 1173.667647: fence:fence_enable_signal: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56910 >>>>>>> swapper 0 [007] 1173.667688: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56900 >>>>>>> swapper 0 [007] 1173.667692: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56900 >>>>>>> swapper 0 [007] 1173.667839: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56901 >>>>>>> swapper 0 [007] 1173.667842: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56901 >>>>>>> swapper 0 [007] 1173.668021: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56902 >>>>>>> swapper 0 [007] 1173.668482: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56903 >>>>>>> swapper 0 [007] 1173.668485: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56903 >>>>>>> swapper 0 [007] 1173.668489: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56904 >>>>>>> swapper 0 [007] 1173.668496: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56905 >>>>>>> swapper 0 [007] 1173.668499: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56905 >>>>>>> swapper 0 [007] 1173.668502: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56906 >>>>>>> swapper 0 [007] 1173.668505: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56907 >>>>>>> swapper 0 [007] 1173.668508: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56907 >>>>>>> swapper 0 [007] 1173.668511: fence:fence_signaled: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56908 >>>>>>> swapper 0 [007] 1173.668513: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56908 >>>>>>> kworker/4:1 80 [004] 1173.676265: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56896 >>>>>>> kworker/4:1 80 [004] 1173.676273: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56898 >>>>>>> kworker/4:1 80 [004] 1173.676277: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56902 >>>>>>> kworker/4:1 80 [004] 1173.676280: fence:fence_destroy: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56904 >>>>>>> Xorg 474 [001] 1188.676067: fence:fence_wait_end: >>>>>>> driver=nouveau timeline=Xorg[474] context=2 seqno=56910 >>>>>>> >>>>>>> I assume that excludes the context you really want so the full fence >>>>>>> event log and corresponding dmesg output are attached. >>>>>> Yep, the trace events are useful. The fence is emitted and presumably >>>> no event is fired after emission. >>>>>> Lets find out if the nvif crap is buggy or it's a result of some other >>>> issue, what happens when you change: >>>>>> .wait = fence_default_wait, >>>>>> to >>>>>> .wait = nouveau_fence_wait_legacy, >>>>>> in nouveau_fence.c? >>>>> That change works just fine. >>>> The xorg hangs also appear to be resolved by db1cf46 "drm/nouveau: use rcu >>>> in nouveau_gem_ioctl_cpu_prep" >>>> >>> Oh right, I just remembered what was going on there.. >>> the .wait was a workaround for a bug in the nvif interface. The hangs should be resolved by applying >>> 7caa63c04029c5882865867470c106ef73eafb2b >>> >>> Can you confirm? >>> >>> Could you also confirm that 1c6aafb5f1b84fa5 "drm/nouveau: use shared fences for readable objects, EDITED" with the >>> above commit applied is the first broken commit? >>> >>> ~Maarten >>> >> I don't follow, 7caa63c04029c5882865867470c106ef73eafb2b precedes >> those other commits so there is nothing to apply. Just for kicks I >> tried reverting it but that made no difference in behavior. Did you >> mean something else? >> > No, Maarten brought me on the same track, missing that this commit was already in that branch. > > (Please don't remove me from this thread again, as Maarten requested me to do the same he asked you to do, just easier to follow this, thanks) > > Tobias > Ok that most likely means the interrupt based wait is borked somehow, so lets find out why.. I fear that this happens because of a race in the interface, so my first attempt will rule out abuse of the nvif api by nouveau_fence.c Can you test below patch with the default wait function? diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c index 515cd9aebb99..c1a4ffebc206 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fence.c +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c @@ -52,20 +52,27 @@ nouveau_fctx(struct nouveau_fence *fence) return container_of(fence->base.lock, struct nouveau_fence_chan, lock); } -static void -nouveau_fence_signal(struct nouveau_fence *fence) +static int +nouveau_fence_signal(struct nouveau_fence *fence, int delay) { + int drop = 0; + fence_signal_locked(&fence->base); list_del(&fence->head); if (test_bit(FENCE_FLAG_USER_BITS, &fence->base.flags)) { struct nouveau_fence_chan *fctx = nouveau_fctx(fence); - if (!--fctx->notify_ref) - nvif_notify_put(&fctx->notify); + if (!--fctx->notify_ref) { + if (!delay) + nvif_notify_put(&fctx->notify); + else + drop = 1; + } } fence_put(&fence->base); + return drop; } static struct nouveau_fence * @@ -94,7 +101,7 @@ nouveau_fence_context_del(struct nouveau_fence_chan *fctx) while (!list_empty(&fctx->pending)) { fence = list_entry(fctx->pending.next, typeof(*fence), head); - nouveau_fence_signal(fence); + nouveau_fence_signal(fence, 0); fence->channel = NULL; } spin_unlock_irq(&fctx->lock); @@ -112,10 +119,11 @@ nouveau_fence_context_free(struct nouveau_fence_chan *fctx) kref_put(&fctx->fence_ref, nouveau_fence_context_put); } -static void -nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx) +static int +nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx, int delay) { struct nouveau_fence *fence; + int drop = 0; u32 seq = fctx->read(chan); @@ -123,10 +131,12 @@ nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fc fence = list_entry(fctx->pending.next, typeof(*fence), head); if ((int)(seq - fence->base.seqno) < 0) - return; + break; - nouveau_fence_signal(fence); + drop |= nouveau_fence_signal(fence, delay); } + + return drop; } static int @@ -135,18 +145,20 @@ nouveau_fence_wait_uevent_handler(struct nvif_notify *notify) struct nouveau_fence_chan *fctx = container_of(notify, typeof(*fctx), notify); unsigned long flags; + int ret = NVIF_NOTIFY_KEEP; spin_lock_irqsave(&fctx->lock, flags); if (!list_empty(&fctx->pending)) { struct nouveau_fence *fence; fence = list_entry(fctx->pending.next, typeof(*fence), head); - nouveau_fence_update(fence->channel, fctx); + if (nouveau_fence_update(fence->channel, fctx, 1)) + ret = NVIF_NOTIFY_DROP; } spin_unlock_irqrestore(&fctx->lock, flags); /* Always return keep here. NVIF refcount is handled with nouveau_fence_update */ - return NVIF_NOTIFY_KEEP; + return ret; } void @@ -262,7 +274,7 @@ nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan) if (!ret) { fence_get(&fence->base); spin_lock_irq(&fctx->lock); - nouveau_fence_update(chan, fctx); + nouveau_fence_update(chan, fctx, 0); list_add_tail(&fence->head, &fctx->pending); spin_unlock_irq(&fctx->lock); } @@ -282,7 +294,7 @@ nouveau_fence_done(struct nouveau_fence *fence) return true; spin_lock_irqsave(&fctx->lock, flags); - nouveau_fence_update(fence->channel, fctx); + nouveau_fence_update(fence->channel, fctx, 0); spin_unlock_irqrestore(&fctx->lock, flags); } return fence_is_signaled(&fence->base); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/