From ab108d992b1248adfb7c13c1136cab59c944a98c Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 1 Jul 2020 20:45:04 +0200 Subject: btrfs: use precalculated sectorsize_bits from fs_info We do a lot of calculations where we divide or multiply by sectorsize. We also know and make sure that sectorsize is a power of two, so this means all divisions can be turned to shifts and avoid eg. expensive u64/u32 divisions. The type is u32 as it's more register friendly on x86_64 compared to u8 and the resulting assembly is smaller (movzbl vs movl). There's also superblock s_blocksize_bits but it's usually one more pointer dereference farther than fs_info. Reviewed-by: Johannes Thumshirn Signed-off-by: David Sterba --- fs/btrfs/tests/btrfs-tests.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/btrfs/tests/btrfs-tests.c') diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c index 999c14e5d0bd..b36e88753f1f 100644 --- a/fs/btrfs/tests/btrfs-tests.c +++ b/fs/btrfs/tests/btrfs-tests.c @@ -134,6 +134,7 @@ struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(u32 nodesize, u32 sectorsize) fs_info->nodesize = nodesize; fs_info->sectorsize = sectorsize; + fs_info->sectorsize_bits = ilog2(sectorsize); set_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state); test_mnt->mnt_sb->s_fs_info = fs_info; -- cgit v1.2.3