Re: [PATCH] MIPS: smp: optimization for flush_tlb_mm when exiting

From: Thomas Bogendoerfer
Date: Thu May 12 2022 - 12:12:08 EST


On Tue, May 10, 2022 at 07:44:41PM +0800, Mao Bibo wrote:
> When process exits or execute new binary, it will call function
> exit_mmap with old mm, there is such function call trace:
> exit_mmap(struct mm_struct *mm)
> --> tlb_finish_mmu(&tlb, 0, -1)
> --> arch_tlb_finish_mmu(tlb, start, end, force)
> --> tlb_flush_mmu(tlb);
> --> tlb_flush(struct mmu_gather *tlb)
> --> flush_tlb_mm(tlb->mm)
>
> It is not necessary to flush tlb since oldmm is not used anymore
> by the process, there is similar operations on IA64/ARM64 etc,
> this patch adds such optimization on MIPS.
>
> Signed-off-by: Mao Bibo <maobibo@xxxxxxxxxxx>
> ---
> arch/mips/kernel/smp.c | 6 ++++++
> 1 file changed, 6 insertions(+)

applied to mips-next.

Thomas.

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