Re: [Xen-devel] [PATCH v5 1/2] xen: replace tlbflush check and operation with inline functions

[Jan Beulich]

>>> On 19.09.16 at 04:50,  wrote:
> This patch cleaned up the code by replacing complicated tlbflush check and
> operation with inline functions. We should use those inline functions to
> avoid the complicated tlbflush check and tlbflush operations when
> implementing TODOs left in commit a902c12ee45fc9389eb8fe54eeddaf267a555c58
> (More efficient TLB-flush filtering in alloc_heap_pages()).
> 
> "#include " is removed from xen/arch/x86/acpi/suspend.c to
> avoid the compiling error after we include "" to
> xen/include/xen/mm.h.
> 
> Signed-off-by: Dongli Zhang 
> ---
> Changed since v4:
>   * Wrap the filtered tlbflush mask operation as inline function (suggested
> by Jan).

That was only one half of my request, the other half was to ...

> --- a/xen/common/page_alloc.c
> +++ b/xen/common/page_alloc.c
> @@ -827,10 +827,8 @@ static struct page_info *alloc_heap_pages(
>  BUG_ON(pg[i].count_info != PGC_state_free);
>  pg[i].count_info = PGC_state_inuse;
>  
> -if ( pg[i].u.free.need_tlbflush &&
> - (pg[i].tlbflush_timestamp <= tlbflush_current_time()) &&
> - (!need_tlbflush ||
> -  (pg[i].tlbflush_timestamp > tlbflush_timestamp)) )
> +if ( accumulate_tlbflush(need_tlbflush, [i],
> + tlbflush_timestamp) )
>  {
>  need_tlbflush = 1;
>  tlbflush_timestamp = pg[i].tlbflush_timestamp;

... also move the if() including its body into the helper (whether you
make the new value of need_tlbflush the return value or handle it
via indirection is up to you).

Jan


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[Xen-devel] [PATCH v5 1/2] xen: replace tlbflush check and operation with inline functions

[Dongli Zhang]

This patch cleaned up the code by replacing complicated tlbflush check and
operation with inline functions. We should use those inline functions to
avoid the complicated tlbflush check and tlbflush operations when
implementing TODOs left in commit a902c12ee45fc9389eb8fe54eeddaf267a555c58
(More efficient TLB-flush filtering in alloc_heap_pages()).

"#include " is removed from xen/arch/x86/acpi/suspend.c to
avoid the compiling error after we include "" to
xen/include/xen/mm.h.

Signed-off-by: Dongli Zhang 
---
Changed since v4:
  * Wrap the filtered tlbflush mask operation as inline function (suggested
by Jan).
  * Remove asm/flushtlb.h from suspend.c to avoid compiling error.

Changed since v3:
  * Wrap the complicated tlbflush condition check as inline function
(suggested by Dario).

---
 xen/arch/x86/acpi/suspend.c |  1 -
 xen/common/page_alloc.c | 16 +++-
 xen/include/xen/mm.h| 25 +
 3 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/xen/arch/x86/acpi/suspend.c b/xen/arch/x86/acpi/suspend.c
index 1d8344c..d5c67ee 100644
--- a/xen/arch/x86/acpi/suspend.c
+++ b/xen/arch/x86/acpi/suspend.c
@@ -10,7 +10,6 @@
 #include 
 #include 
 #include 
-#include 
 #include 
 #include 
 #include 
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 18ff6cf..173c10d 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -827,10 +827,8 @@ static struct page_info *alloc_heap_pages(
 BUG_ON(pg[i].count_info != PGC_state_free);
 pg[i].count_info = PGC_state_inuse;
 
-if ( pg[i].u.free.need_tlbflush &&
- (pg[i].tlbflush_timestamp <= tlbflush_current_time()) &&
- (!need_tlbflush ||
-  (pg[i].tlbflush_timestamp > tlbflush_timestamp)) )
+if ( accumulate_tlbflush(need_tlbflush, [i],
+ tlbflush_timestamp) )
 {
 need_tlbflush = 1;
 tlbflush_timestamp = pg[i].tlbflush_timestamp;
@@ -849,15 +847,7 @@ static struct page_info *alloc_heap_pages(
 spin_unlock(_lock);
 
 if ( need_tlbflush )
-{
-cpumask_t mask = cpu_online_map;
-tlbflush_filter(mask, tlbflush_timestamp);
-if ( !cpumask_empty() )
-{
-perfc_incr(need_flush_tlb_flush);
-flush_tlb_mask();
-}
-}
+filtered_flush_tlb_mask(tlbflush_timestamp);
 
 return pg;
 }
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index f470e49..85848e3 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -51,6 +51,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 
 TYPE_SAFE(unsigned long, mfn);
@@ -567,4 +568,28 @@ int prepare_ring_for_helper(struct domain *d, unsigned 
long gmfn,
 struct page_info **_page, void **_va);
 void destroy_ring_for_helper(void **_va, struct page_info *page);
 
+#include 
+
+static inline bool accumulate_tlbflush(bool need_tlbflush,
+   const struct page_info *page,
+   uint32_t tlbflush_timestamp)
+{
+return page->u.free.need_tlbflush &&
+   page->tlbflush_timestamp <= tlbflush_current_time() &&
+   (!need_tlbflush ||
+page->tlbflush_timestamp > tlbflush_timestamp);
+}
+
+static inline void filtered_flush_tlb_mask(uint32_t tlbflush_timestamp)
+{
+cpumask_t mask = cpu_online_map;
+
+tlbflush_filter(mask, tlbflush_timestamp);
+if ( !cpumask_empty() )
+{
+perfc_incr(need_flush_tlb_flush);
+flush_tlb_mask();
+}
+}
+
 #endif /* __XEN_MM_H__ */
-- 
1.9.1


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