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<body><span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI] igt@gem_exec_schedule@preempt-* - dmesg-warn - WARN_ON_ONCE((1) && !(preempt_count() != 0))"
href="https://bugs.freedesktop.org/show_bug.cgi?id=106977">bug 106977</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
</td>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>FIXED
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI] igt@gem_exec_schedule@preempt-* - dmesg-warn - WARN_ON_ONCE((1) && !(preempt_count() != 0))"
href="https://bugs.freedesktop.org/show_bug.cgi?id=106977#c2">Comment # 2</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI] igt@gem_exec_schedule@preempt-* - dmesg-warn - WARN_ON_ONCE((1) && !(preempt_count() != 0))"
href="https://bugs.freedesktop.org/show_bug.cgi?id=106977">bug 106977</a>
from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
<pre>commit 26eb4cd6c7c7793ee76c73b66621f63daff51953
Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
Date: Wed Jun 20 14:59:29 2018 +0100
drm/i915: Disable bh around call to tasklet
The guc submission backends expects to only be run from (at least)
softirq context, but during our intel_engine_is_idle() check we would
call into the tasklet to make sure it was flushed. As this could occur
from process context, occasionally we would be caught out using a
wait_for_atomic() not from an atomic context:
[ 59.939091] WARN_ON_ONCE((1) && !(preempt_count() != 0))
[ 59.939142] WARNING: CPU: 1 PID: 2901 at
drivers/gpu/drm/i915/intel_guc_submission.c:615
guc_submission_tasklet+0x784/0xa90 [i915]
[ 59.939143] Modules linked in: vgem snd_hda_codec_hdmi
snd_hda_codec_realtek snd_hda_codec_generic i915 x86_pkg_temp_thermal
intel_powerclamp coretemp crct10dif_pclmul snd_hda_intel crc32_pclmul
snd_hda_codec ghash_clmulni_intel snd_hwdep snd_hda_core e1000e snd_pcm mei_me
mei prime_numbers
[ 59.939164] CPU: 1 PID: 2901 Comm: gem_exec_schedu Tainted: G U W
4.18.0-rc1-g93475d62c730-drmtip_67+ #1
[ 59.939165] Hardware name: System manufacturer System Product
Name/Z170M-PLUS, BIOS 3610 03/29/2018
[ 59.939188] RIP: 0010:guc_submission_tasklet+0x784/0xa90 [i915]
[ 59.939189] Code: fc ff ff 80 3d 2f 87 11 00 00 0f 85 80 fb ff ff 48 c7
c6 f8 49 40 c0 48 c7 c7 80 41 3e c0 c6 05 14 87 11 00 01 e8 2c ea d6 d3 <0f> 0b
e9 5f fb ff ff 8b 46 38 89 cf 31 c7 83 e7 c0 75 08 39 c1 0f
[ 59.939253] RSP: 0018:ffffaafe08a03c10 EFLAGS: 00010286
[ 59.939255] RAX: 0000000000000000 RBX: ffff8f9112c246f0 RCX:
0000000000000001
[ 59.939256] RDX: 0000000080000001 RSI: ffffffff95086d8e RDI:
00000000ffffffff
[ 59.939257] RBP: ffff8f9112c24680 R08: 000000009517be77 R09:
0000000000000000
[ 59.939258] R10: 0000000000000000 R11: 0000000000000000 R12:
ffff8f9112c24700
[ 59.939259] R13: ffff8f9112c24700 R14: 0000000000000000 R15:
ffff8f9112c242a8
[ 59.939260] FS: 00007fc2cc7e5980(0000) GS:ffff8f9136c40000(0000)
knlGS:0000000000000000
[ 59.939261] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 59.939262] CR2: 00007fc2cc815040 CR3: 000000021f10e003 CR4:
00000000003606e0
[ 59.939263] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 59.939264] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 59.939265] Call Trace:
[ 59.939288] ? intel_engine_is_idle+0x64/0x160 [i915]
[ 59.939323] ? intel_engine_dump+0x638/0x890 [i915]
[ 59.939327] ? seq_printf+0x49/0x70
[ 59.939353] ? i915_engine_info+0xc8/0x100 [i915]
[ 59.939356] ? drm_get_color_range_name+0x20/0x20
[ 59.939361] ? seq_read+0xf1/0x470
[ 59.939365] ? trace_hardirqs_on_caller+0xe0/0x1b0
[ 59.939370] ? full_proxy_read+0x51/0x80
[ 59.939389] ? __vfs_read+0x31/0x170
[ 59.939395] ? do_sys_open+0x13b/0x240
[ 59.939398] ? rcu_read_lock_sched_held+0x6f/0x80
[ 59.939401] ? vfs_read+0x9e/0x140
[ 59.939404] ? ksys_read+0x50/0xc0
[ 59.939409] ? do_syscall_64+0x55/0x190
[ 59.939412] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 59.939420] irq event stamp: 552834
[ 59.939422] hardirqs last enabled at (552833): [<ffffffff940fc74c>]
console_unlock+0x3fc/0x600
[ 59.939425] hardirqs last disabled at (552834): [<ffffffff94a0111c>]
error_entry+0x7c/0x100
[ 59.939451] softirqs last enabled at (552614): [<ffffffffc02e0f53>]
i915_request_add+0x2e3/0x7b0 [i915]
[ 59.939470] softirqs last disabled at (552604): [<ffffffffc02e0ecb>]
i915_request_add+0x25b/0x7b0 [i915]
Bugzilla: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI] igt@gem_exec_schedule@preempt-* - dmesg-warn - WARN_ON_ONCE((1) && !(preempt_count() != 0))"
href="show_bug.cgi?id=106977">https://bugs.freedesktop.org/show_bug.cgi?id=106977</a>
Fixes: dd0cf235d81f ("drm/i915: Speed up idle detection by kicking the
tasklets")
Signed-off-by: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
Cc: Tvrtko Ursulin <<a href="mailto:tvrtko.ursulin@intel.com">tvrtko.ursulin@intel.com</a>>
Cc: Mika Kuoppala <<a href="mailto:mika.kuoppala@linux.intel.com">mika.kuoppala@linux.intel.com</a>>
Cc: Michal Wajdeczko <<a href="mailto:michal.wajdeczko@intel.com">michal.wajdeczko@intel.com</a>>
Cc: Michał Winiarski <<a href="mailto:michal.winiarski@intel.com">michal.winiarski@intel.com</a>>
Cc: Michel Thierry <<a href="mailto:michel.thierry@intel.com">michel.thierry@intel.com</a>>
Reviewed-by: Michel Thierry <<a href="mailto:michel.thierry@intel.com">michel.thierry@intel.com</a>>
Link:
<a href="https://patchwork.freedesktop.org/patch/msgid/20180620135929.23956-1-chris@chris-wilson.co.uk">https://patchwork.freedesktop.org/patch/msgid/20180620135929.23956-1-chris@chris-wilson.co.uk</a></pre>
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