The patch titled Subject: powerpc/64s: enable MMU_LAZY_TLB_SHOOTDOWN has been added to the -mm tree. Its filename is powerpc-64s-enable-mmu_lazy_tlb_shootdown.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/powerpc-64s-enable-mmu_lazy_tlb_shootdown.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/powerpc-64s-enable-mmu_lazy_tlb_shootdown.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Nicholas Piggin <npiggin@xxxxxxxxx> Subject: powerpc/64s: enable MMU_LAZY_TLB_SHOOTDOWN On a 16-socket 192-core POWER8 system, a context switching benchmark with as many software threads as CPUs (so each switch will go in and out of idle), upstream can achieve a rate of about 1 million context switches per second. After this patch it goes up to 118 million. Link: https://lkml.kernel.org/r/20210605014216.446867-5-npiggin@xxxxxxxxx Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Anton Blanchard <anton@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/powerpc/Kconfig | 1 + 1 file changed, 1 insertion(+) --- a/arch/powerpc/Kconfig~powerpc-64s-enable-mmu_lazy_tlb_shootdown +++ a/arch/powerpc/Kconfig @@ -252,6 +252,7 @@ config PPC select IRQ_FORCED_THREADING select MMU_GATHER_PAGE_SIZE select MMU_GATHER_RCU_TABLE_FREE + select MMU_LAZY_TLB_SHOOTDOWN if PPC_BOOK3S_64 select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE if PPC64 || NOT_COHERENT_CACHE select NEED_SG_DMA_LENGTH _ Patches currently in -mm which might be from npiggin@xxxxxxxxx are lazy-tlb-introduce-lazy-mm-refcount-helper-functions.patch lazy-tlb-allow-lazy-tlb-mm-refcounting-to-be-configurable.patch lazy-tlb-shoot-lazies-a-non-refcounting-lazy-tlb-option.patch powerpc-64s-enable-mmu_lazy_tlb_shootdown.patch