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SubjectRe: [PATCH v10 7/9] x86/tlb: enable tlb flush range support for x86
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Separate is better.  When I say clean patch I mean in a separate email so git am can process it.

Alex Shi <alex.shi@intel.com> wrote:

>On 07/20/2012 07:56 AM, H. Peter Anvin wrote:
>
>> On 07/19/2012 04:52 PM, Alex Shi wrote:
>>>
>>> Sure, it is a bug, the fix had sent:
>>> https://lkml.org/lkml/2012/7/6/350
>>>
>>
>> Could you please re-send that as a clean patch?
>>
>> -hpa
>>
>
>
>
>
>Since, it has not impact for the serial left patches, and linux-next
>has not merge this patchset. I folded this patch into original.
>Is that ok, or need a separated one?
>
>===
>From 2e6117dfda5b323261e959bb5faf778cbe4b3c64 Mon Sep 17 00:00:00 2001
>From: Alex Shi <alex.shi@intel.com>
>Date: Mon, 25 Jun 2012 11:06:46 +0800
>Subject: [PATCH 7/9] x86/tlb: enable tlb flush range support for x86
>
>Not every tlb_flush execution moment is really need to evacuate all
>TLB entries, like in munmap, just few 'invlpg' is better for whole
>process performance, since it leaves most of TLB entries for later
>accessing.
>
>This patch also rewrite flush_tlb_range for 2 purposes:
>1, split it out to get flush_blt_mm_range function.
>2, clean up to reduce line breaking, thanks for Borislav's input.
>
>My micro benchmark 'mummap' http://lkml.org/lkml/2012/5/17/59
>show that the random memory access on other CPU has 0~50% speed up
>on a 2P * 4cores * HT NHM EP while do 'munmap'.
>
>Thanks Yongjie's testing on this patch:
>-------------
>I used Linux 3.4-RC6 w/ and w/o his patches as Xen dom0 and guest
>kernel.
>After running two benchmarks in Xen HVM guest, I found his patches
>brought about 1%~3% performance gain in 'kernel build' and 'netperf'
>testing, though the performance gain was not very stable in 'kernel
>build' testing.
>
>Some detailed testing results are below.
>
>Testing Environment:
> Hardware: Romley-EP platform
> Xen version: latest upstream
> Linux kernel: 3.4-RC6
> Guest vCPU number: 8
> NIC: Intel 82599 (10GB bandwidth)
>
>In 'kernel build' testing in guest:
> Command line | performance gain
> make -j 4 | 3.81%
> make -j 8 | 0.37%
> make -j 16 | -0.52%
>
>In 'netperf' testing, we tested TCP_STREAM with default socket size
>16384 byte as large packet and 64 byte as small packet.
>I used several clients to add networking pressure, then 'netperf'
>server
>automatically generated several threads to response them.
>I also used large-size packet and small-size packet in the testing.
> Packet size | Thread number | performance gain
> 16384 bytes | 4 | 0.02%
> 16384 bytes | 8 | 2.21%
> 16384 bytes | 16 | 2.04%
> 64 bytes | 4 | 1.07%
> 64 bytes | 8 | 3.31%
> 64 bytes | 16 | 0.71%
>
>This patch also fold a flush_tlb_mm_range() fixing in 'make
>allnoconfig'
>, that reported by Tetsuo Handa. Thanks!
>
>Signed-off-by: Alex Shi <alex.shi@intel.com>
>Tested-by: Ren, Yongjie <yongjie.ren@intel.com>
>---
> arch/x86/include/asm/tlb.h | 9 +++-
> arch/x86/include/asm/tlbflush.h | 17 +++++-
>arch/x86/mm/tlb.c | 112
>++++++++++++++++-----------------------
> 3 files changed, 68 insertions(+), 70 deletions(-)
>
>diff --git a/arch/x86/include/asm/tlb.h b/arch/x86/include/asm/tlb.h
>index 829215f..4fef207 100644
>--- a/arch/x86/include/asm/tlb.h
>+++ b/arch/x86/include/asm/tlb.h
>@@ -4,7 +4,14 @@
> #define tlb_start_vma(tlb, vma) do { } while (0)
> #define tlb_end_vma(tlb, vma) do { } while (0)
> #define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
>-#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
>+
>+#define tlb_flush(tlb) \
>+{ \
>+ if (tlb->fullmm == 0) \
>+ flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end, 0UL); \
>+ else \
>+ flush_tlb_mm_range(tlb->mm, 0UL, TLB_FLUSH_ALL, 0UL); \
>+}
>
> #include <asm-generic/tlb.h>
>
>diff --git a/arch/x86/include/asm/tlbflush.h
>b/arch/x86/include/asm/tlbflush.h
>index 33608d9..4fc8faf 100644
>--- a/arch/x86/include/asm/tlbflush.h
>+++ b/arch/x86/include/asm/tlbflush.h
>@@ -105,6 +105,13 @@ static inline void flush_tlb_range(struct
>vm_area_struct *vma,
> __flush_tlb();
> }
>
>+static inline void flush_tlb_mm_range(struct mm_struct *mm,
>+ unsigned long start, unsigned long end, unsigned long vmflag)
>+{
>+ if (mm == current->active_mm)
>+ __flush_tlb();
>+}
>+
>static inline void native_flush_tlb_others(const struct cpumask
>*cpumask,
> struct mm_struct *mm,
> unsigned long start,
>@@ -122,12 +129,16 @@ static inline void reset_lazy_tlbstate(void)
>
> #define local_flush_tlb() __flush_tlb()
>
>+#define flush_tlb_mm(mm) flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL,
>0UL)
>+
>+#define flush_tlb_range(vma, start, end) \
>+ flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags)
>+
> extern void flush_tlb_all(void);
> extern void flush_tlb_current_task(void);
>-extern void flush_tlb_mm(struct mm_struct *);
> extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
>-extern void flush_tlb_range(struct vm_area_struct *vma,
>- unsigned long start, unsigned long end);
>+extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long
>start,
>+ unsigned long end, unsigned long vmflag);
>
> #define flush_tlb() flush_tlb_current_task()
>
>diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
>index 5911f61..481737d 100644
>--- a/arch/x86/mm/tlb.c
>+++ b/arch/x86/mm/tlb.c
>@@ -301,23 +301,10 @@ void flush_tlb_current_task(void)
> preempt_enable();
> }
>
>-void flush_tlb_mm(struct mm_struct *mm)
>-{
>- preempt_disable();
>-
>- if (current->active_mm == mm) {
>- if (current->mm)
>- local_flush_tlb();
>- else
>- leave_mm(smp_processor_id());
>- }
>- if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
>- flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
>-
>- preempt_enable();
>-}
>-
>-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
>+/*
>+ * It can find out the THP large page, or
>+ * HUGETLB page in tlb_flush when THP disabled
>+ */
> static inline unsigned long has_large_page(struct mm_struct *mm,
> unsigned long start, unsigned long end)
> {
>@@ -339,68 +326,61 @@ static inline unsigned long has_large_page(struct
>mm_struct *mm,
> }
> return 0;
> }
>-#else
>-static inline unsigned long has_large_page(struct mm_struct *mm,
>- unsigned long start, unsigned long end)
>-{
>- return 0;
>-}
>-#endif
>-void flush_tlb_range(struct vm_area_struct *vma,
>- unsigned long start, unsigned long end)
>-{
>- struct mm_struct *mm;
>
>- if (vma->vm_flags & VM_HUGETLB || tlb_flushall_shift == -1) {
>-flush_all:
>- flush_tlb_mm(vma->vm_mm);
>- return;
>- }
>+void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
>+ unsigned long end, unsigned long vmflag)
>+{
>+ unsigned long addr;
>+ unsigned act_entries, tlb_entries = 0;
>
> preempt_disable();
>- mm = vma->vm_mm;
>- if (current->active_mm == mm) {
>- if (current->mm) {
>- unsigned long addr, vmflag = vma->vm_flags;
>- unsigned act_entries, tlb_entries = 0;
>+ if (current->active_mm != mm)
>+ goto flush_all;
>
>- if (vmflag & VM_EXEC)
>- tlb_entries = tlb_lli_4k[ENTRIES];
>- else
>- tlb_entries = tlb_lld_4k[ENTRIES];
>-
>- act_entries = tlb_entries > mm->total_vm ?
>- mm->total_vm : tlb_entries;
>+ if (!current->mm) {
>+ leave_mm(smp_processor_id());
>+ goto flush_all;
>+ }
>
>- if ((end - start) >> PAGE_SHIFT >
>- act_entries >> tlb_flushall_shift)
>- local_flush_tlb();
>- else {
>- if (has_large_page(mm, start, end)) {
>- preempt_enable();
>- goto flush_all;
>- }
>- for (addr = start; addr < end;
>- addr += PAGE_SIZE)
>- __flush_tlb_single(addr);
>+ if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1
>+ || vmflag == VM_HUGETLB) {
>+ local_flush_tlb();
>+ goto flush_all;
>+ }
>
>- 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;
>- }
>- } else {
>- leave_mm(smp_processor_id());
>+ /* In modern CPU, last level tlb used for both data/ins */
>+ if (vmflag & VM_EXEC)
>+ tlb_entries = tlb_lli_4k[ENTRIES];
>+ else
>+ tlb_entries = tlb_lld_4k[ENTRIES];
>+ /* Assume all of TLB entries was occupied by this task */
>+ act_entries = mm->total_vm > tlb_entries ? tlb_entries :
>mm->total_vm;
>+
>+ /* tlb_flushall_shift is on balance point, details in commit log */
>+ if ((end - start) >> PAGE_SHIFT > act_entries >> tlb_flushall_shift)
>+ local_flush_tlb();
>+ else {
>+ if (has_large_page(mm, start, end)) {
>+ local_flush_tlb();
>+ goto flush_all;
> }
>+ /* flush range by one by one 'invlpg' */
>+ for (addr = start; addr < end; addr += PAGE_SIZE)
>+ __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:
> if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
> flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
> preempt_enable();
> }
>
>-
> void flush_tlb_page(struct vm_area_struct *vma, unsigned long start)
> {
> struct mm_struct *mm = vma->vm_mm;
>--
>1.7.5.4

--
Sent from my mobile phone. Please excuse brevity and lack of formatting.


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