git: 44121a0fbee0 - main - amd64: fix tlb shootdown when all cpus are passed in the bitmap

[John Baldwin]

On 1/12/21 12:54 AM, Mateusz Guzik wrote:
> The branch main has been updated by mjg:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=44121a0fbee0272e23bfb90601d177ba9e9cda9b
> 
> commit 44121a0fbee0272e23bfb90601d177ba9e9cda9b
> Author:     Mateusz Guzik <mjg at FreeBSD.org>
> AuthorDate: 2021-01-12 08:47:32 +0000
> Commit:     Mateusz Guzik <mjg at FreeBSD.org>
> CommitDate: 2021-01-12 08:47:32 +0000
> 
>     amd64: fix tlb shootdown when all cpus are passed in the bitmap
>     
>     Right now the routine leaves the current CPU in the map, later tripping
>     on an assert when filling in the scoreboard: panic: IPI scoreboard is
>     zero, initiator 1 target 1
>     
>     Instead pre-check if all CPUs are present in the map and remember that
>     outcome for later.
>     
>     Fixes:  7eaea04a5bb1dc86 ("amd64: compare TLB shootdown target to all_cpus")
>     Reviewed by:    kib
>     Differential Revision:  https://reviews.freebsd.org/D28111
> ---
>  sys/amd64/amd64/mp_machdep.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
> index 794a11bf1276..aa62c2086fa4 100644
> --- a/sys/amd64/amd64/mp_machdep.c
> +++ b/sys/amd64/amd64/mp_machdep.c
> @@ -660,6 +660,7 @@ smp_targeted_tlb_shootdown(cpuset_t mask, pmap_t pmap, vm_offset_t addr1,
>  	 * (zeroing slot) and reading from it below (wait for
>  	 * acknowledgment).
>  	 */
> -	if (!CPU_CMP(&mask, &all_cpus)) {
> +	if (is_all) {
>  		ipi_all_but_self(IPI_INVLOP);
>  		other_cpus = all_cpus;
>  		CPU_CLR(PCPU_GET(cpuid), &other_cpus);

At this point isn't other_cpus == mask, so we could just drop other_cpus and use 'mask'
directly now?

-- 
John Baldwin