From 62dbec78be652c28f63ad5eda3d01c244c916040 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 7 Nov 2005 14:09:58 -0800 Subject: [PATCH] [SPARC64] mm: Do not flush TLB mm in tlb_finish_mmu() It isn't needed any longer, as noted by Hugh Dickins. We still need the flush routines, due to the one remaining call site in hugetlb_prefault_arch_hook(). That can be eliminated at some later point, however. Signed-off-by: David S. Miller --- arch/sparc64/kernel/smp.c | 48 ++++++++++++++------------------------- include/asm-sparc64/tlb.h | 6 ++--- 2 files changed, 19 insertions(+), 35 deletions(-) diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c index a9089e2140e9..5d90ee9aebf1 100644 --- a/arch/sparc64/kernel/smp.c +++ b/arch/sparc64/kernel/smp.c @@ -839,43 +839,29 @@ void smp_flush_tlb_all(void) * questionable (in theory the big win for threads is the massive sharing of * address space state across processors). */ + +/* This currently is only used by the hugetlb arch pre-fault + * hook on UltraSPARC-III+ and later when changing the pagesize + * bits of the context register for an address space. + */ void smp_flush_tlb_mm(struct mm_struct *mm) { - /* - * This code is called from two places, dup_mmap and exit_mmap. In the - * former case, we really need a flush. In the later case, the callers - * are single threaded exec_mmap (really need a flush), multithreaded - * exec_mmap case (do not need to flush, since the caller gets a new - * context via activate_mm), and all other callers of mmput() whence - * the flush can be optimized since the associated threads are dead and - * the mm is being torn down (__exit_mm and other mmput callers) or the - * owning thread is dissociating itself from the mm. The - * (atomic_read(&mm->mm_users) == 0) check ensures real work is done - * for single thread exec and dup_mmap cases. An alternate check might - * have been (current->mm != mm). - * Kanoj Sarcar - */ - if (atomic_read(&mm->mm_users) == 0) - return; - - { - u32 ctx = CTX_HWBITS(mm->context); - int cpu = get_cpu(); + u32 ctx = CTX_HWBITS(mm->context); + int cpu = get_cpu(); - if (atomic_read(&mm->mm_users) == 1) { - mm->cpu_vm_mask = cpumask_of_cpu(cpu); - goto local_flush_and_out; - } + if (atomic_read(&mm->mm_users) == 1) { + mm->cpu_vm_mask = cpumask_of_cpu(cpu); + goto local_flush_and_out; + } - smp_cross_call_masked(&xcall_flush_tlb_mm, - ctx, 0, 0, - mm->cpu_vm_mask); + smp_cross_call_masked(&xcall_flush_tlb_mm, + ctx, 0, 0, + mm->cpu_vm_mask); - local_flush_and_out: - __flush_tlb_mm(ctx, SECONDARY_CONTEXT); +local_flush_and_out: + __flush_tlb_mm(ctx, SECONDARY_CONTEXT); - put_cpu(); - } + put_cpu(); } void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long *vaddrs) diff --git a/include/asm-sparc64/tlb.h b/include/asm-sparc64/tlb.h index 66138d959df5..1eda17954f39 100644 --- a/include/asm-sparc64/tlb.h +++ b/include/asm-sparc64/tlb.h @@ -78,11 +78,9 @@ static inline void tlb_finish_mmu(struct mmu_gather *mp, unsigned long start, un { tlb_flush_mmu(mp); - if (mp->fullmm) { - if (CTX_VALID(mp->mm->context)) - do_flush_tlb_mm(mp->mm); + if (mp->fullmm) mp->fullmm = 0; - } else + else flush_tlb_pending(); /* keep the page table cache within bounds */ -- 2.20.1