[Xen-changelog] [qemu-xen-unstable] mapcache: remember the last page address rather then the last address_index

[patchbot@xxxxxxx]

commit e3073b9dbf3217f619a4537197067231111d400e
Author: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Date:   Tue Jun 21 18:05:10 2011 +0100

    mapcache: remember the last page address rather then the last address_index
    
    A single address_index corresponds to multiple pages that might or
    might not be mapped.  It is better to just remember the last page
    address for the sake of this optimization, so that we are sure that it
    is mapped.
    
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
 hw/xen_machine_fv.c |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/xen_machine_fv.c b/hw/xen_machine_fv.c
index a353ee6..603a508 100644
--- a/hw/xen_machine_fv.c
+++ b/hw/xen_machine_fv.c
@@ -63,7 +63,7 @@ static unsigned long nr_buckets;
 TAILQ_HEAD(map_cache_head, map_cache_rev) locked_entries = 
TAILQ_HEAD_INITIALIZER(locked_entries);
 
 /* For most cases (>99.9%), the page address is the same. */
-static unsigned long last_address_index = ~0UL;
+static unsigned long last_address_page = ~0UL;
 static uint8_t      *last_address_vaddr;
 
 static int qemu_map_cache_init(void)
@@ -138,7 +138,7 @@ uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, 
uint8_t lock)
     unsigned long address_index  = phys_addr >> MCACHE_BUCKET_SHIFT;
     unsigned long address_offset = phys_addr & (MCACHE_BUCKET_SIZE-1);
 
-    if (address_index == last_address_index && !lock)
+    if ((phys_addr >> XC_PAGE_SHIFT) == last_address_page && !lock)
         return last_address_vaddr + address_offset;
 
     entry = &mapcache_entry[address_index % nr_buckets];
@@ -157,17 +157,17 @@ uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, 
uint8_t lock)
     }
 
     if (!test_bit(address_offset>>XC_PAGE_SHIFT, entry->valid_mapping)) {
-        last_address_index = ~0UL;
+        last_address_page = ~0UL;
         return NULL;
     }
 
-    last_address_index = address_index;
+    last_address_page = phys_addr >> XC_PAGE_SHIFT;
     last_address_vaddr = entry->vaddr_base;
     if (lock) {
         struct map_cache_rev *reventry = qemu_mallocz(sizeof(struct 
map_cache_rev));
         entry->lock++;
         reventry->vaddr_req = last_address_vaddr + address_offset;
-        reventry->paddr_index = last_address_index;
+        reventry->paddr_index = address_index;
         TAILQ_INSERT_TAIL(&locked_entries, reventry, next);
     }
 
@@ -182,7 +182,7 @@ void qemu_invalidate_entry(uint8_t *buffer)
     int found = 0;
     
     if (last_address_vaddr == buffer)
-        last_address_index =  ~0UL;
+        last_address_page =  ~0UL;
 
     TAILQ_FOREACH(reventry, &locked_entries, next) {
         if (reventry->vaddr_req == buffer) {
@@ -252,7 +252,7 @@ void qemu_invalidate_map_cache(void)
         entry->vaddr_base  = NULL;
     }
 
-    last_address_index =  ~0UL;
+    last_address_page =  ~0UL;
     last_address_vaddr = NULL;
 
     mapcache_unlock();
--
generated by git-patchbot for /home/xen/git/qemu-xen-unstable.git

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