Btrfs: reduce mount -o ssd CPU usage

The block allocator in SSD mode will try to find groups of free blocks
that are close together.  This commit makes it loop less on a given
group size before bumping it.

The end result is that we are less likely to fill small holes in the
available free space, but we don't waste as much CPU building the
large cluster used by ssd mode.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2009-05-18 10:41:58 -04:00
parent cfbb930846
commit 2c943de6ad

View File

@ -652,7 +652,7 @@ again:
last = entry; last = entry;
max_extent = 0; max_extent = 0;
total_retries++; total_retries++;
if (total_retries % 256 == 0) { if (total_retries % 64 == 0) {
if (min_bytes >= (bytes + empty_size)) { if (min_bytes >= (bytes + empty_size)) {
ret = -ENOSPC; ret = -ENOSPC;
goto out; goto out;