Re: [PATCH v2] sched/debug: Use sched_debug_lock to serialize use of cgroup_path[] only

2021-03-30 Thread Waiman Long
On 3/30/21 6:42 AM, Daniel Thompson wrote: On Mon, Mar 29, 2021 at 03:32:35PM -0400, Waiman Long wrote: The handling of sysrq keys should normally be done in an user context except when MAGIC_SYSRQ_SERIAL is set and the magic sequence is typed in a serial console. This seems to be a poor

Re: [PATCH v2] sched/debug: Use sched_debug_lock to serialize use of cgroup_path[] only

2021-03-30 Thread Daniel Thompson
On Mon, Mar 29, 2021 at 03:32:35PM -0400, Waiman Long wrote: > The handling of sysrq keys should normally be done in an user context > except when MAGIC_SYSRQ_SERIAL is set and the magic sequence is typed > in a serial console. This seems to be a poor summary of the typical calling context for

[PATCH v2] sched/debug: Use sched_debug_lock to serialize use of cgroup_path[] only

2021-03-29 Thread Waiman Long
The handling of sysrq keys should normally be done in an user context except when MAGIC_SYSRQ_SERIAL is set and the magic sequence is typed in a serial console. Currently in print_cpu() of kernel/sched/debug.c, sched_debug_lock is taken with interrupt disabled for the whole duration of the calls