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Message-Id: <20140421182420.307A0C57@viggo.jf.intel.com>
Date: Mon, 21 Apr 2014 11:24:20 -0700
From: Dave Hansen <dave@...1.net>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
akpm@...ux-foundation.org, kirill.shutemov@...ux.intel.com,
mgorman@...e.de, ak@...ux.intel.com, riel@...hat.com,
alex.shi@...aro.org, Dave Hansen <dave@...1.net>,
dave.hansen@...ux.intel.com
Subject: [PATCH 1/6] 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 2014-04-21 11:10:34.431818610 -0700
+++ b/arch/x86/mm/tlb.c 2014-04-21 11:10:34.435818791 -0700
@@ -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();
}
_
--
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