[PATCH 31/35] xfs: invert the realtime summary cache

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Omar Sandoval <osandov@xxxxxx>

Source kernel commit: e23aaf450de733044a74bc95528f728478b61c2a

In commit 355e3532132b ("xfs: cache minimum realtime summary level"), I
added a cache of the minimum level of the realtime summary that has any
free extents. However, it turns out that the _maximum_ level is more
useful for upcoming optimizations, and basically equivalent for the
existing usage. So, let's change the meaning of the cache to be the
maximum level + 1, or 0 if there are no free extents.

For example, if the cache contains:

{0, 4}

then there are no free extents starting in realtime bitmap block 0, and
there are no free extents larger than or equal to 2^4 blocks starting in
realtime bitmap block 1. The cache is a loose upper bound, so there may
or may not be free extents smaller than 2^4 blocks in realtime bitmap
block 1.

Signed-off-by: Omar Sandoval <osandov@xxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Carlos Maiolino <cem@xxxxxxxxxx>
---
 libxfs/xfs_rtbitmap.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libxfs/xfs_rtbitmap.c b/libxfs/xfs_rtbitmap.c
index f5d7e14ab..8f313339e 100644
--- a/libxfs/xfs_rtbitmap.c
+++ b/libxfs/xfs_rtbitmap.c
@@ -493,10 +493,10 @@ xfs_rtmodify_summary_int(
 		xfs_suminfo_t	val = xfs_suminfo_add(args, infoword, delta);
 
 		if (mp->m_rsum_cache) {
-			if (val == 0 && log == mp->m_rsum_cache[bbno])
-				mp->m_rsum_cache[bbno]++;
-			if (val != 0 && log < mp->m_rsum_cache[bbno])
+			if (val == 0 && log + 1 == mp->m_rsum_cache[bbno])
 				mp->m_rsum_cache[bbno] = log;
+			if (val != 0 && log >= mp->m_rsum_cache[bbno])
+				mp->m_rsum_cache[bbno] = log + 1;
 		}
 		xfs_trans_log_rtsummary(args, infoword);
 		if (sum)
-- 
2.43.0





[Index of Archives]     [XFS Filesystem Development (older mail)]     [Linux Filesystem Development]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux RAID]     [Linux SCSI]


  Powered by Linux