Commit ec39780d authored by Shrikanth Hegde's avatar Shrikanth Hegde Committed by Thomas Gleixner
Browse files

smp: Get this_cpu once in smp_call_function 



smp_call_function_single() and smp_call_function_many_cond() disable
preemption and cache the CPU number via get_cpu().

Use this cached value throughout the function instead of invoking
smp_processor_id() again.

[ tglx: Make the copy&pasta'ed change log match the patch ]

Signed-off-by: default avatarShrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@kernel.org>
Reviewed-by: default avatarMukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Link: https://patch.msgid.link/20260323193630.640311-4-sshegde@linux.ibm.com
parent cc562394

kernel/smp.c

+2 −2
Original line number Diff line number Diff line
@@ -678,7 +678,7 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, 
	csd->func = func;

	csd->info = info;

#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG

	csd->node.src = smp_processor_id();

	csd->node.src = this_cpu;

	csd->node.dst = cpu;

#endif
@@ -833,7 +833,7 @@ static void smp_call_function_many_cond(const struct cpumask *mask, 
			csd->func = func;

			csd->info = info;

#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG

			csd->node.src = smp_processor_id();

			csd->node.src = this_cpu;

			csd->node.dst = cpu;

#endif

			trace_csd_queue_cpu(cpu, _RET_IP_, func, csd);