https://bugzilla.kernel.org/show_bug.cgi?id=169241
Bug ID: 169241 Summary: AC to battery causes extreme load, many kworker threads in D state Product: ACPI Version: 2.5 Kernel Version: 4.4.0, 4.6.3 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Power-Battery Assignee: acpi_power-batt...@kernel-bugs.osdl.org Reporter: spambox+kernel...@thisblueroom.net Regression: No SYNOPSIS Most of the time, disconnecting a 2008 Macbook from AC, or reconnecting it to AC, will cause hundreds of kworker threads to be spawned, driving up system load to levels where a GUI may become unusable. CPU and iowait is low. kworker threads are in D state. 'powertop' shows increased numbers of ACPI interrupts, and acpi_ec_event_processor and acpi_os_execute_deferred very high ms/s figures in the Usage column. This is occurring on Lubuntu 16.04. The bug is present in the 4.4.0 distribution kernel and in kernel 4.6.3-yakkety from the Ubuntu kernel PPA. Booting with acpi=off renders critical portions of the system unusable. See also: https://ubuntuforums.org/showthread.php?t=2335053&p=13544491 RELATED INFO 'top': top - 21:29:22 up 1 day, 5:57, 2 users, load average: 223.67, 179.10, 166.01 Tasks: 448 total, 1 running, 447 sleeping, 0 stopped, 0 zombie %Cpu(s): 4.3 us, 1.0 sy, 0.0 ni, 94.5 id, 0.2 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem : 4011084 total, 557060 free, 2009348 used, 1444676 buff/cache KiB Swap: 2999804 total, 2607704 free, 392100 used. 1574160 avail Mem $ ps ax | grep kworker | wc -l 271 $ ps -e -o state,pid,cmd | grep ^D | grep kworker | wc -l 257 'powertop' before power source change: Summary: 294.0 wakeups/second, 2.1 GPU ops/seconds, 0.0 VFS ops/sec and 6.7% CPU use Usage Events/s Category Description 100.0% Device Audio codec hwC0D0: Realtek 6.0 ms/s 54.1 Process /usr/lib/chromium-browser/chromium-browser --enable-pinch 38.0 ms/s 48.5 Process /usr/lib/chromium-browser/chromium-browser --type=renderer --enable-pinch --enable-features=D 362.1 µs/s 29.8 kWork dbs_timer 1.6 ms/s 27.3 Interrupt [9] acpi 'powertop' two refreshes after power source change: Summary: 300.8 wakeups/second, 3.8 GPU ops/seconds, 0.0 VFS ops/sec and 1084.8% CPU use Usage Events/s Category Description 9627 ms/s 9.9 kWork acpi_ec_event_processor 1138 ms/s 16.3 kWork acpi_os_execute_deferred 13.8 ms/s 236.5 Interrupt [9] acpi 100.0% Device Audio codec hwC0D0: Realtek -- You are receiving this mail because: You are watching the assignee of the bug. ------------------------------------------------------------------------------ _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla