Messages in this thread Patch in this message | | | Date | Mon, 24 Feb 2020 15:01:37 +0100 | From | Thomas Gleixner <> | Subject | [patch V3 06/22] bpf/trace: Remove redundant preempt_disable from trace_call_bpf() |
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Similar to __bpf_trace_run this is redundant because __bpf_trace_run() is invoked from a trace point via __DO_TRACE() which already disables preemption _before_ invoking any of the functions which are attached to a trace point.
Remove it and add a cant_sleep() check.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- V3: New patch. Replaces the previous one which converted this to migrate_disable() --- kernel/trace/bpf_trace.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -83,7 +83,7 @@ unsigned int trace_call_bpf(struct trace if (in_nmi()) /* not supported yet */ return 1; - preempt_disable(); + cant_sleep(); if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { /* @@ -115,7 +115,6 @@ unsigned int trace_call_bpf(struct trace out: __this_cpu_dec(bpf_prog_active); - preempt_enable(); return ret; }
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