Re: [patch] agp: don't lock pages

From: Bret Towe
Date: Wed Jul 25 2007 - 14:44:30 EST


On 7/25/07, Nick Piggin <npiggin@xxxxxxx> wrote:
Hi,

Does this patch solve the X problem? Does anyone see anything wrong
with it or know why agp was locking the pages?

Yeap the mac mini is happy again
Thanks

--
AGP should not need to lock pages. They are not protecting any race
because there is no lock_page calls, only SetPageLocked.

This is causing hangs with d00806b183152af6d24f46f0c33f14162ca1262a.

Signed-off-by: Nick Piggin <npiggin@xxxxxxx>

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index d535c40..3db4f40 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -1170,7 +1170,6 @@ void *agp_generic_alloc_page(struct agp_
map_page_into_agp(page);

get_page(page);
- SetPageLocked(page);
atomic_inc(&agp_bridge->current_memory_agp);
return page_address(page);
}
@@ -1187,7 +1186,6 @@ void agp_generic_destroy_page(void *addr
page = virt_to_page(addr);
unmap_page_from_agp(page);
put_page(page);
- unlock_page(page);
free_page((unsigned long)addr);
atomic_dec(&agp_bridge->current_memory_agp);
}
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index a124060..2f319f4 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -213,7 +213,6 @@ static void *i8xx_alloc_pages(void)
}
global_flush_tlb();
get_page(page);
- SetPageLocked(page);
atomic_inc(&agp_bridge->current_memory_agp);
return page_address(page);
}
@@ -229,7 +228,6 @@ static void i8xx_destroy_pages(void *add
change_page_attr(page, 4, PAGE_KERNEL);
global_flush_tlb();
put_page(page);
- unlock_page(page);
__free_pages(page, 2);
atomic_dec(&agp_bridge->current_memory_agp);
}
diff --git a/drivers/char/agp/sgi-agp.c b/drivers/char/agp/sgi-agp.c
index cda608c..98cf8ab 100644
--- a/drivers/char/agp/sgi-agp.c
+++ b/drivers/char/agp/sgi-agp.c
@@ -51,7 +51,6 @@ static void *sgi_tioca_alloc_page(struct
return NULL;

get_page(page);
- SetPageLocked(page);
atomic_inc(&agp_bridge->current_memory_agp);
return page_address(page);
}
-
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