When something let __find_get_block_slow() hit all_mapped path, it calls
printk() for 100+ times per a second. But there is no need to print same
message with such high frequency; it is just asking for stall warning, or
at least bloating log files.
[ 399.866302][T15342] __find_get_block_slow() failed. block=1, b_blocknr=8
[ 399.873324][T15342] b_state=0x00000029, b_size=512
[ 399.878403][T15342] device loop0 blocksize: 4096
[ 399.883296][T15342] __find_get_block_slow() failed. block=1, b_blocknr=8
[ 399.890400][T15342] b_state=0x00000029, b_size=512
[ 399.895595][T15342] device loop0 blocksize: 4096
[ 399.900556][T15342] __find_get_block_slow() failed. block=1, b_blocknr=8
[ 399.907471][T15342] b_state=0x00000029, b_size=512
[ 399.912506][T15342] device loop0 blocksize: 4096
This patch reduces frequency to approximately once per a second, in
addition to concatenating three lines into one. This patch uses plain
time_in_range() than __ratelimit(), for there is no need to allocate
space for debug objects in ratelimit_state.lock field.
[ 399.866302][T15342] __find_get_block_slow() failed. block=1, b_blocknr=8, b_state=0x00000029, b_size=512, device loop0 blocksize: 4096
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 52d024b..3fc9167 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -200,6 +200,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
struct buffer_head *head;
struct page *page;
int all_mapped = 1;
+ static unsigned long last;
index = block >> (PAGE_SHIFT - bd_inode->i_blkbits);
page = find_get_page_flags(bd_mapping, index, FGP_ACCESSED);
@@ -227,15 +228,13 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
* file io on the block device and getblk. It gets dealt with
* elsewhere, don't buffer_error if we had some unmapped buffers
*/
- if (all_mapped) {
- printk("__find_get_block_slow() failed. "
- "block=%llu, b_blocknr=%llu\n",
- (unsigned long long)block,
- (unsigned long long)bh->b_blocknr);
- printk("b_state=0x%08lx, b_size=%zu\n",
- bh->b_state, bh->b_size);
- printk("device %pg blocksize: %d\n", bdev,
- 1 << bd_inode->i_blkbits);
+ if (all_mapped && !time_in_range(jiffies, last, last + HZ)) {
+ printk("__find_get_block_slow() failed. block=%llu, b_blocknr=%llu, b_state=0x%08lx, b_size=%zu, device %pg blocksize: %d\n",
+ (unsigned long long)block,
+ (unsigned long long)bh->b_blocknr,
+ bh->b_state, bh->b_size, bdev,
+ 1 << bd_inode->i_blkbits);
+ last = jiffies;
}
out_unlock:
spin_unlock(&bd_mapping->private_lock);
--
1.8.3.1
