On 8/29/2012 6:03 PM, Laura Abbott wrote:
My quick and dirty workaround for testing is to remove the GFP_MOVABLE
flag from find_or_create_page but this seems significantly less than
optimal. Ideally, it seems like the buffers should be evicted from the
LRU when trying to drop (expand on invalid_bh_lru?) but I'm not familiar
enough with the code path to know if this is a good approach.
Any suggestions/feedback is appreciated. Thanks.
Laura
I came up with what I think is a reasonable fix to this. Feedback is
appreciated. Thanks.
Laura
8<---
diff --git a/fs/buffer.c b/fs/buffer.c
index ad5938c..daa0c3d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1399,12 +1399,49 @@ static bool has_bh_in_lru(int cpu, void *dummy)
return 0;
}
+static void __evict_bh_lru(void *arg)
+{
+ struct bh_lru *b = &get_cpu_var(bh_lrus);
+ struct buffer_head *bh = arg;
+ int i;
+
+ for (i = 0; i < BH_LRU_SIZE; i++) {
+ if (b->bhs[i] == bh) {
+ brelse(b->bhs[i]);
+ b->bhs[i] = NULL;
+ goto out;
+ }
+ }
+out:
+ put_cpu_var(bh_lrus);
+}
+
+static bool bh_exists_in_lru(int cpu, void *arg)
+{
+ struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu);
+ struct buffer_head *bh = arg;
+ int i;
+
+ for (i = 0; i < BH_LRU_SIZE; i++) {
+ if (b->bhs[i] == bh)
+ return 1;
+ }
+
+ return 0;
+
+}
void invalidate_bh_lrus(void)
{
on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1, GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(invalidate_bh_lrus);
+void evict_bh_lrus(struct buffer_head *bh)
+{
+ on_each_cpu_cond(bh_exists_in_lru, __evict_bh_lru, bh, 1, GFP_ATOMIC);
+}
+EXPORT_SYMBOL_GPL(evict_bh_lrus);
+
void set_bh_page(struct buffer_head *bh,
struct page *page, unsigned long offset)
{
@@ -3052,6 +3089,7 @@ drop_buffers(struct page *page, struct buffer_head
**buffers_to_free)
bh = head;
do {
+ evict_bh_lrus(bh);
if (buffer_write_io_error(bh) && page->mapping)
set_bit(AS_EIO, &page->mapping->flags);
if (buffer_busy(bh))
--
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
