Created attachment 161741 [details] dmesg This is a regression, it doesn't happen with kernel-debug-3.18.1-2.fc22.i686. 3.19.0 kernel build method listed below. Problem: Two processes are using 100% CPU. PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 227 root 20 0 0 0 0 R 49.7 0.0 2:40.84 pccardd 232 root 20 0 0 0 0 R 49.7 0.0 2:40.59 pccardd And I get this trace. Attaching complete dmesg, and lspci. [ 5.958090] ------------[ cut here ]------------ [ 5.958167] WARNING: CPU: 0 PID: 227 at kernel/sched/core.c:7303 __might_sleep+0xb8/0xd0() [ 5.958269] do not call blocking ops when !TASK_RUNNING; state=1 set at [<c08e9c30>] pccardd+0xc0/0x450 [ 5.958367] Modules linked in: ttm drm ptp ata_generic yenta_socket pata_acpi pps_core uas usb_storage [ 5.958690] CPU: 0 PID: 227 Comm: pccardd Not tainted 3.19.0-rc1cmbtrfsdebug #1 [ 5.958785] Hardware name: Dell Computer Corporation Latitude D600 /0G5152, BIOS A16 06/29/2005 [ 5.958884] 00000000 c5084202 00000000 f49abe08 c0b3e64f f49abe4c f49abe3c c045e13b [ 5.959180] c0d169e0 f49abe6c 000000e3 c0d23cb4 00001c87 c0487ab8 00001c87 c0487ab8 [ 5.959447] 00000001 f533c230 f533c230 f49abe58 c045e1ae 00000009 f49abe4c c0d169e0 [ 5.959715] Call Trace: [ 5.959779] [<c0b3e64f>] dump_stack+0x48/0x60 [ 5.959844] [<c045e13b>] warn_slowpath_common+0x8b/0xc0 [ 5.959907] [<c0487ab8>] ? __might_sleep+0xb8/0xd0 [ 5.959969] [<c0487ab8>] ? __might_sleep+0xb8/0xd0 [ 5.960051] [<c045e1ae>] warn_slowpath_fmt+0x3e/0x60 [ 5.960114] [<c0487ab8>] __might_sleep+0xb8/0xd0 [ 5.960176] [<c08e9c30>] ? pccardd+0xc0/0x450 [ 5.960238] [<c08e9c30>] ? pccardd+0xc0/0x450 [ 5.960303] [<c0b42f1e>] mutex_lock_nested+0x2e/0x3e0 [ 5.960368] [<c04b331c>] ? trace_hardirqs_on_caller+0x13c/0x1e0 [ 5.960433] [<c04b33cb>] ? trace_hardirqs_on+0xb/0x10 [ 5.960496] [<c08e9c8e>] pccardd+0x11e/0x450 [ 5.960559] [<c08e9b70>] ? pcmcia_socket_dev_complete+0x40/0x40 [ 5.960626] [<c048022d>] kthread+0xcd/0xe0 [ 5.960688] [<c04b33cb>] ? trace_hardirqs_on+0xb/0x10 [ 5.960752] [<c0b47401>] ret_from_kernel_thread+0x21/0x30 [ 5.960816] [<c0480160>] ? kthread_create_on_node+0x180/0x180 [ 5.960879] ---[ end trace 232873d0de401016 ]---
Created attachment 161751 [details] lspci
Source acquired from git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git. From linux directory, make menuconfig was used to load a Fedora kernel configuration config-3.18.0-2.fc22.i686+debug, enable CONFIG_BTRFS_DEBUG, CONFIG_BTRFS_ASSERT then saved, and kernel built.