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authorAlan Hourihane <alanh@fairlite.demon.co.uk>2005-11-06 23:35:34 -0800
committerDave Jones <davej@redhat.com>2005-11-08 13:43:54 -0800
commit88d51967f56f55a45849efe50858ea7dfa0d38dc (patch)
tree048db8e12c2b31ec2b88c3154da4c6a77b80028c
parent329f7dba5f7dc3bc9a30ad00cf373d2e83115aa1 (diff)
downloadop-kernel-dev-88d51967f56f55a45849efe50858ea7dfa0d38dc.zip
op-kernel-dev-88d51967f56f55a45849efe50858ea7dfa0d38dc.tar.gz
[PATCH] AGP performance fixes
AGP allocation/deallocation is suffering major performance issues due to the nature of global_flush_tlb() being called on every change_page_attr() call. For small allocations this isn't really seen, but when you start allocating 50000 pages of AGP space, for say, texture memory, then things can take seconds to complete. In some cases the situation is doubled or even quadrupled in the time due to SMP, or a deallocation, then a new reallocation. I've had a case of upto 20 seconds wait time to deallocate and reallocate AGP space. This patch fixes the problem by making it the caller's responsibility to call global_flush_tlb(), and so removes it from every instance of mapping a page into AGP space until the time that all change_page_attr() changes are done. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
-rw-r--r--drivers/char/agp/backend.c9
-rw-r--r--drivers/char/agp/generic.c11
-rw-r--r--drivers/char/agp/i460-agp.c9
-rw-r--r--drivers/char/agp/intel-agp.c5
4 files changed, 25 insertions, 9 deletions
diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index 73f333f..4d5ed18 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -147,6 +147,7 @@ static int agp_backend_initialize(struct agp_bridge_data *bridge)
printk(KERN_ERR PFX "unable to get memory for scratch page.\n");
return -ENOMEM;
}
+ global_flush_tlb();
bridge->scratch_page_real = virt_to_gart(addr);
bridge->scratch_page =
@@ -187,9 +188,11 @@ static int agp_backend_initialize(struct agp_bridge_data *bridge)
return 0;
err_out:
- if (bridge->driver->needs_scratch_page)
+ if (bridge->driver->needs_scratch_page) {
bridge->driver->agp_destroy_page(
gart_to_virt(bridge->scratch_page_real));
+ global_flush_tlb();
+ }
if (got_gatt)
bridge->driver->free_gatt_table(bridge);
if (got_keylist) {
@@ -211,9 +214,11 @@ static void agp_backend_cleanup(struct agp_bridge_data *bridge)
bridge->key_list = NULL;
if (bridge->driver->agp_destroy_page &&
- bridge->driver->needs_scratch_page)
+ bridge->driver->needs_scratch_page) {
bridge->driver->agp_destroy_page(
gart_to_virt(bridge->scratch_page_real));
+ global_flush_tlb();
+ }
}
/* When we remove the global variable agp_bridge from all drivers
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index c4a3871..19f242b 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -57,7 +57,8 @@ int map_page_into_agp(struct page *page)
{
int i;
i = change_page_attr(page, 1, PAGE_KERNEL_NOCACHE);
- global_flush_tlb();
+ /* Caller's responsibility to call global_flush_tlb() for
+ * performance reasons */
return i;
}
EXPORT_SYMBOL_GPL(map_page_into_agp);
@@ -66,7 +67,8 @@ int unmap_page_from_agp(struct page *page)
{
int i;
i = change_page_attr(page, 1, PAGE_KERNEL);
- global_flush_tlb();
+ /* Caller's responsibility to call global_flush_tlb() for
+ * performance reasons */
return i;
}
EXPORT_SYMBOL_GPL(unmap_page_from_agp);
@@ -153,6 +155,7 @@ void agp_free_memory(struct agp_memory *curr)
for (i = 0; i < curr->page_count; i++) {
curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]));
}
+ global_flush_tlb();
}
agp_free_key(curr->key);
vfree(curr->memory);
@@ -210,7 +213,9 @@ struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge,
new->memory[i] = virt_to_gart(addr);
new->page_count++;
}
- new->bridge = bridge;
+ global_flush_tlb();
+
+ new->bridge = bridge;
flush_agp_mappings();
diff --git a/drivers/char/agp/i460-agp.c b/drivers/char/agp/i460-agp.c
index 58944cd..be2e569 100644
--- a/drivers/char/agp/i460-agp.c
+++ b/drivers/char/agp/i460-agp.c
@@ -514,9 +514,10 @@ static void *i460_alloc_page (struct agp_bridge_data *bridge)
{
void *page;
- if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
+ if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
page = agp_generic_alloc_page(agp_bridge);
- else
+ global_flush_tlb();
+ } else
/* Returning NULL would cause problems */
/* AK: really dubious code. */
page = (void *)~0UL;
@@ -525,8 +526,10 @@ static void *i460_alloc_page (struct agp_bridge_data *bridge)
static void i460_destroy_page (void *page)
{
- if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
+ if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
agp_generic_destroy_page(page);
+ global_flush_tlb();
+ }
}
#endif /* I460_LARGE_IO_PAGES */
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index bf4cc9f..027161a 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -270,6 +270,7 @@ static struct agp_memory *alloc_agpphysmem_i8xx(size_t pg_count, int type)
switch (pg_count) {
case 1: addr = agp_bridge->driver->agp_alloc_page(agp_bridge);
+ global_flush_tlb();
break;
case 4:
/* kludge to get 4 physical pages for ARGB cursor */
@@ -330,9 +331,11 @@ static void intel_i810_free_by_type(struct agp_memory *curr)
if(curr->type == AGP_PHYS_MEMORY) {
if (curr->page_count == 4)
i8xx_destroy_pages(gart_to_virt(curr->memory[0]));
- else
+ else {
agp_bridge->driver->agp_destroy_page(
gart_to_virt(curr->memory[0]));
+ global_flush_tlb();
+ }
vfree(curr->memory);
}
kfree(curr);
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