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| author | John Snow <jsnow@redhat.com> | 2015-04-17 19:49:54 -0400 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2015-04-28 15:36:10 +0200 |
| commit | 8515efbef1759b9143f06e9722c8f4e145032181 (patch) | |
| tree | d7058da418daf26e724613e2e515b8b816e10945 /util | |
| parent | 592fdd02ae987a439a2ba25a2a973673f1484805 (diff) | |
| download | qemu-8515efbef1759b9143f06e9722c8f4e145032181.zip | |
hbitmap: cache array lengths
As a convenience: between incremental backups, bitmap migrations
and bitmap persistence we seem to need to recalculate these a lot.
Because the lengths are a little bit-twiddly, let's just solidly
cache them and be done with it.
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1429314609-29776-7-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'util')
| -rw-r--r-- | util/hbitmap.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/util/hbitmap.c b/util/hbitmap.c index ab139717f5..5b78613400 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -90,6 +90,9 @@ struct HBitmap { * bitmap will still allocate HBITMAP_LEVELS arrays. */ unsigned long *levels[HBITMAP_LEVELS]; + + /* The length of each levels[] array. */ + uint64_t sizes[HBITMAP_LEVELS]; }; /* Advance hbi to the next nonzero word and return it. hbi->pos @@ -384,6 +387,7 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity) hb->granularity = granularity; for (i = HBITMAP_LEVELS; i-- > 0; ) { size = MAX((size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1); + hb->sizes[i] = size; hb->levels[i] = g_new0(unsigned long, size); } |