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Date: Wed, 05 Mar 2014 16:45:21 -0800 From: Dave Hansen <dave@...1.net> To: linux-kernel@...r.kernel.org Cc: akpm@...ux-foundation.org, ak@...ux.intel.com, kirill.shutemov@...ux.intel.com, mgorman@...e.de, alex.shi@...aro.org, x86@...nel.org, linux-mm@...ck.org, Dave Hansen <dave@...1.net>, dave.hansen@...ux.intel.com Subject: [PATCH 1/7] x86: mm: clean up tlb flushing code From: Dave Hansen <dave.hansen@...ux.intel.com> The if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) line of code is not exactly the easiest to audit, especially when it ends up at two different indentation levels. This eliminates one of the the copy-n-paste versions. It also gives us a unified exit point for each path through this function. We need this in a minute for our tracepoint. Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com> --- b/arch/x86/mm/tlb.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff -puN arch/x86/mm/tlb.c~simplify-tlb-code arch/x86/mm/tlb.c --- a/arch/x86/mm/tlb.c~simplify-tlb-code 2014-03-05 16:10:09.607047728 -0800 +++ b/arch/x86/mm/tlb.c 2014-03-05 16:10:09.610047866 -0800 @@ -161,23 +161,24 @@ void flush_tlb_current_task(void) void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, unsigned long end, unsigned long vmflag) { + int need_flush_others_all = 1; unsigned long addr; unsigned act_entries, tlb_entries = 0; unsigned long nr_base_pages; preempt_disable(); if (current->active_mm != mm) - goto flush_all; + goto out; if (!current->mm) { leave_mm(smp_processor_id()); - goto flush_all; + goto out; } if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1 || vmflag & VM_HUGETLB) { local_flush_tlb(); - goto flush_all; + goto out; } /* In modern CPU, last level tlb used for both data/ins */ @@ -196,22 +197,20 @@ void flush_tlb_mm_range(struct mm_struct count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); local_flush_tlb(); } else { + need_flush_others_all = 0; /* flush range by one by one 'invlpg' */ for (addr = start; addr < end; addr += PAGE_SIZE) { count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE); __flush_tlb_single(addr); } - - if (cpumask_any_but(mm_cpumask(mm), - smp_processor_id()) < nr_cpu_ids) - flush_tlb_others(mm_cpumask(mm), mm, start, end); - preempt_enable(); - return; } - -flush_all: +out: + if (need_flush_others_all) { + start = 0UL; + end = TLB_FLUSH_ALL; + } if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) - flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL); + flush_tlb_others(mm_cpumask(mm), mm, start, end); preempt_enable(); } _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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