dcd0b625fe
With the RAPL PMU addition, there is a recursive locking when CPU online
callback function calls rapl_package_add_pmu(). Here cpu_hotplug_lock
is already acquired by cpuhp_thread_fun() and rapl_package_add_pmu()
tries to acquire again.
<4>[ 8.197433] ============================================
<4>[ 8.197437] WARNING: possible recursive locking detected
<4>[ 8.197440] 6.19.0-rc1-lgci-xe-xe-4242-05b7c58b3367dca84+ #1 Not tainted
<4>[ 8.197444] --------------------------------------------
<4>[ 8.197447] cpuhp/0/20 is trying to acquire lock:
<4>[ 8.197450] ffffffff83487870 (cpu_hotplug_lock){++++}-{0:0}, at:
rapl_package_add_pmu+0x37/0x370 [intel_rapl_common]
<4>[ 8.197463]
but task is already holding lock:
<4>[ 8.197466] ffffffff83487870 (cpu_hotplug_lock){++++}-{0:0}, at:
cpuhp_thread_fun+0x6d/0x290
<4>[ 8.197477]
other info that might help us debug this:
<4>[ 8.197480] Possible unsafe locking scenario:
<4>[ 8.197483] CPU0
<4>[ 8.197485] ----
<4>[ 8.197487] lock(cpu_hotplug_lock);
<4>[ 8.197490] lock(cpu_hotplug_lock);
<4>[ 8.197493]
*** DEADLOCK ***
..
..
<4>[ 8.197542] __lock_acquire+0x146e/0x2790
<4>[ 8.197548] lock_acquire+0xc4/0x2c0
<4>[ 8.197550] ? rapl_package_add_pmu+0x37/0x370 [intel_rapl_common]
<4>[ 8.197556] cpus_read_lock+0x41/0x110
<4>[ 8.197558] ? rapl_package_add_pmu+0x37/0x370 [intel_rapl_common]
<4>[ 8.197561] rapl_package_add_pmu+0x37/0x370 [intel_rapl_common]
<4>[ 8.197565] rapl_cpu_online+0x85/0x87 [intel_rapl_msr]
<4>[ 8.197568] ? __pfx_rapl_cpu_online+0x10/0x10 [intel_rapl_msr]
<4>[ 8.197570] cpuhp_invoke_callback+0x41f/0x6c0
<4>[ 8.197573] ? cpuhp_thread_fun+0x6d/0x290
<4>[ 8.197575] cpuhp_thread_fun+0x1e2/0x290
<4>[ 8.197578] ? smpboot_thread_fn+0x26/0x290
<4>[ 8.197581] smpboot_thread_fn+0x12f/0x290
<4>[ 8.197584] ? __pfx_smpboot_thread_fn+0x10/0x10
<4>[ 8.197586] kthread+0x11f/0x250
<4>[ 8.197589] ? __pfx_kthread+0x10/0x10
<4>[ 8.197592] ret_from_fork+0x344/0x3a0
<4>[ 8.197595] ? __pfx_kthread+0x10/0x10
<4>[ 8.197597] ret_from_fork_asm+0x1a/0x30
<4>[ 8.197604] </TASK>
Fix this issue in the same way as rapl powercap package domain is added
from the same CPU online callback by introducing another interface which
doesn't call cpus_read_lock(). Add rapl_package_add_pmu_locked() and
rapl_package_remove_pmu_locked() which don't call cpus_read_lock().
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| arm_scmi_powercap.c | ||
| dtpm.c | ||
| dtpm_cpu.c | ||
| dtpm_devfreq.c | ||
| dtpm_subsys.h | ||
| idle_inject.c | ||
| intel_rapl_common.c | ||
| intel_rapl_msr.c | ||
| intel_rapl_tpmi.c | ||
| powercap_sys.c | ||