eebe6446cc
There are typically a lot of PMUs registered, but in many cases only few of them have an event registered (like the "cpu" PMU in the presence of the watchdog). As the mutex is already held, it's safe to just check for existing events before doing the cross CPU call. This change saves tens of milliseconds from kexec time (perceived as steal time during a hypervisor host update), with <2ms remaining for this step in the shutdown. There might be additional potential for parallelization or we could just disable performance monitoring during the actual shutdown and be less graceful about it. Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
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| .. | ||
| Makefile | ||
| callchain.c | ||
| core.c | ||
| hw_breakpoint.c | ||
| hw_breakpoint_test.c | ||
| internal.h | ||
| ring_buffer.c | ||
| uprobes.c | ||