Unverified Commit 8237c524 authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Palmer Dabbelt
Browse files

riscv: Optimize switch_mm by passing "cpu" to flush_icache_deferred() 



Directly passing the cpu to flush_icache_deferred() rather than calling
smp_processor_id() again.

Signed-off-by: default avatarJisheng Zhang <jszhang@kernel.org>
[Palmer: drop the QEMU performance numbers, and update the comment]
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 50bae95e

arch/riscv/mm/context.c

+4 −3
Original line number Diff line number Diff line
@@ -280,11 +280,12 @@ static inline void set_mm(struct mm_struct *mm, unsigned int cpu) 
 * cache flush to be performed before execution resumes on each hart.  This

 * actually performs that local instruction cache flush, which implicitly only

 * refers to the current hart.

 *

 * The "cpu" argument must be the current local CPU number.

 */

static inline void flush_icache_deferred(struct mm_struct *mm)

static inline void flush_icache_deferred(struct mm_struct *mm, unsigned int cpu)

{

#ifdef CONFIG_SMP

	unsigned int cpu = smp_processor_id();

	cpumask_t *mask = &mm->context.icache_stale_mask;



	if (cpumask_test_cpu(cpu, mask)) {
@@ -320,5 +321,5 @@ void switch_mm(struct mm_struct *prev, struct mm_struct *next, 


	set_mm(next, cpu);



	flush_icache_deferred(next);

	flush_icache_deferred(next, cpu);

}