On Tue, Jan 11, 2011 at 11:25 AM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > Maybe the screen just has to be inactive for a longer time: do you do > some dynamic "let's power things down if nothing is changing"? So since this is _almost_ reproducible for me, I tried bisecting it. The bisection is a bit iffy, since it's not entirely clear how long I need to wait for the screen saver to cause the problem, but sine I hit a very similar issue while bisecting, I think it's a pretty solid (partial) bisect. What _seems_ to go on is that after commit b5ba177d8d71 ("drm/i915: Poll for seqno completion if IRQ is disabled") I get that "very chunky behavior". And _before_ that commit I actually get a BUG_ON(), and in fact that bug-on does not happen during normal use, but does trigger when the screen saver runs. So I think the old BUG_ON() is actually the exact same case that then causes the jerky problem for me. NOTE! I didn't do a full bisect. I did verify that commit b5ba177d8d71 does expose the bad behavior, and I also verified that a few commits before that gets the BUG_ON, but there's something like three or four commits in between that I didn't test. But we're literally talking just three commits or so (eg commit 8d5203ca6253 gets that BUG_ON(), and 71f4566084eb is marked as "good" too for me, so the only untested commits are 9097eef024db and b13c2b96bf15). I'll test the merge, but I thought I'd send out this note already at this point, because I'm pretty sure this is it. The BUG_ON() that triggers is appended. And as mentioned, the jerky thing really seems to start happening in the exact same circumstance when this BUG_ON triggered. Linus --- [ 330.023447] ------------[ cut here ]------------ [ 330.025136] kernel BUG at drivers/gpu/drm/i915/intel_ringbuffer.c:354! [ 330.026758] invalid opcode: 0000 [#1] PREEMPT SMP [ 330.028396] last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map [ 330.030040] CPU 2 [ 330.030049] Modules linked in: [last unloaded: scsi_wait_scan] [ 330.033313] [ 330.034929] Pid: 2723, comm: Xorg Not tainted 2.6.37-rc4-00295-g0cdab21 #16 P7H57D-V EVO/System Product Name [ 330.036581] RIP: 0010:[<ffffffff812f1cbd>] [<ffffffff812f1cbd>] render_ring_put_irq+0x20/0x88 [ 330.038266] RSP: 0018:ffff88023e001cf8 EFLAGS: 00010246 [ 330.039937] RAX: 0000000000000000 RBX: ffff88023fcdc030 RCX: 0000000000000000 [ 330.041607] RDX: 0000000000003736 RSI: 0000000000000001 RDI: ffff88023fcdc030 [ 330.043277] RBP: ffff88023e001d18 R08: ffff88023fcdd84c R09: 0000000000000000 [ 330.044917] R10: ffff88023e001cb8 R11: ffff88023e001cc8 R12: ffff88023fcdc000 [ 330.046571] R13: ffff88023ff69000 R14: ffff88023fcdd84c R15: ffff88023fcdc118 [ 330.048193] FS: 00007fe1b6342860(0000) GS:ffff8800bd900000(0000) knlGS:0000000000000000 [ 330.049822] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 330.051450] CR2: 00007f4379961000 CR3: 0000000229d41000 CR4: 00000000000006e0 [ 330.053088] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 330.054726] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 330.056364] Process Xorg (pid: 2723, threadinfo ffff88023e000000, task ffff880229db2c40) [ 330.057991] Stack: [ 330.059610] ffff88023fcdc030 ffff88023fcdc000 00000000000026b7 ffff88023fcdd84c [ 330.061255] ffff88023e001d98 ffffffff812da704 ffff88023e001e18 ffff880200000000 [ 330.062908] 0000000000000000 ffff880229db2c40 ffffffff81051e35 ffff88023e001d50 [ 330.064566] Call Trace: [ 330.066202] [<ffffffff812da704>] i915_gem_throttle_ioctl+0x163/0x1ac [ 330.067863] [<ffffffff81051e35>] ? autoremove_wake_function+0x0/0x34 [ 330.069510] [<ffffffff812ba08f>] drm_ioctl+0x290/0x35c [ 330.071136] [<ffffffff81054f24>] ? lock_hrtimer_base.clone.29+0x24/0x48 [ 330.072769] [<ffffffff812da5a1>] ? i915_gem_throttle_ioctl+0x0/0x1ac [ 330.074397] [<ffffffff81054f24>] ? lock_hrtimer_base.clone.29+0x24/0x48 [ 330.076025] [<ffffffff8153c02c>] ? _raw_spin_unlock_irq+0x2b/0x53 [ 330.077651] [<ffffffff810d2ed9>] do_vfs_ioctl+0x4c1/0x502 [ 330.079252] [<ffffffff810c56cd>] ? fget_light+0x13a/0x31a [ 330.080845] [<ffffffff8100202c>] ? sysret_check+0x27/0x62 [ 330.082416] [<ffffffff810d2f6b>] sys_ioctl+0x51/0x76 [ 330.083964] [<ffffffff81001ffb>] system_call_fastpath+0x16/0x1b [ 330.085501] Code: d7 f3 ab 5b 5b 41 5c 41 5d c9 c3 55 48 89 e5 41 56 41 55 41 54 53 4c 8b 6f 18 41 83 bd e0 02 00 00 00 74 66 8b 47 60 85 c0 75 02 <0f> 0b ff c8 89 47 60 85 c0 75 54 49 8b 9d 98 05 00 00 4c 8d a3 [ 330.087351] RIP [<ffffffff812f1cbd>] render_ring_put_irq+0x20/0x88 [ 330.089039] RSP <ffff88023e001cf8> [ 330.099760] ---[ end trace acfb1e4669bf8ace ]--- [ 330.376659] [drm:drm_release] *ERROR* Device busy: 1 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel