From 3789edffaf0eeea736d50210c842398ad602c9ca Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 17 Aug 2022 16:08:34 -0700 Subject: xfs: use shifting and masking when converting rt extents, if possible Avoid the costs of integer division (32-bit and 64-bit) if the realtime extent size is a power of two. Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_rtbitmap.h | 20 ++++++++++++++++++++ fs/xfs/libxfs/xfs_sb.c | 2 ++ fs/xfs/xfs_linux.h | 12 ++++++++++++ fs/xfs/xfs_mount.h | 2 ++ fs/xfs/xfs_rtalloc.c | 1 + fs/xfs/xfs_trans.c | 4 ++++ 6 files changed, 41 insertions(+) diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h index fbed9ae19c51..08463805ad87 100644 --- a/fs/xfs/libxfs/xfs_rtbitmap.h +++ b/fs/xfs/libxfs/xfs_rtbitmap.h @@ -11,6 +11,9 @@ xfs_rtx_to_rtb( struct xfs_mount *mp, xfs_rtxnum_t rtx) { + if (mp->m_rtxblklog >= 0) + return rtx << mp->m_rtxblklog; + return rtx * mp->m_sb.sb_rextsize; } @@ -19,6 +22,9 @@ xfs_rtxlen_to_extlen( struct xfs_mount *mp, xfs_rtxlen_t rtxlen) { + if (mp->m_rtxblklog >= 0) + return rtxlen << mp->m_rtxblklog; + return rtxlen * mp->m_sb.sb_rextsize; } @@ -28,6 +34,9 @@ xfs_extlen_to_rtxmod( struct xfs_mount *mp, xfs_extlen_t len) { + if (mp->m_rtxblklog >= 0) + return len & mp->m_rtxblkmask; + return len % mp->m_sb.sb_rextsize; } @@ -36,6 +45,9 @@ xfs_extlen_to_rtxlen( struct xfs_mount *mp, xfs_extlen_t len) { + if (mp->m_rtxblklog >= 0) + return len >> mp->m_rtxblklog; + return len / mp->m_sb.sb_rextsize; } @@ -45,6 +57,11 @@ xfs_rtb_to_rtx( xfs_rtblock_t rtbno, xfs_extlen_t *mod) { + if (mp->m_rtxblklog >= 0) { + *mod = rtbno & mp->m_rtxblkmask; + return rtbno >> mp->m_rtxblklog; + } + return div_u64_rem(rtbno, mp->m_sb.sb_rextsize, mod); } @@ -53,6 +70,9 @@ xfs_rtb_to_rtxt( struct xfs_mount *mp, xfs_rtblock_t rtbno) { + if (mp->m_rtxblklog >= 0) + return rtbno >> mp->m_rtxblklog; + return div_u64(rtbno, mp->m_sb.sb_rextsize); } diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c index 537221129b54..504241e51b41 100644 --- a/fs/xfs/libxfs/xfs_sb.c +++ b/fs/xfs/libxfs/xfs_sb.c @@ -952,6 +952,8 @@ xfs_sb_mount_common( mp->m_blockmask = sbp->sb_blocksize - 1; mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG; mp->m_blockwmask = mp->m_blockwsize - 1; + mp->m_rtxblklog = log2_if_power2(sbp->sb_rextsize); + mp->m_rtxblkmask = mask64_if_power2(sbp->sb_rextsize); mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, true); mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, false); diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h index 4b14cf9a750f..4f40e57531ea 100644 --- a/fs/xfs/xfs_linux.h +++ b/fs/xfs/xfs_linux.h @@ -198,6 +198,18 @@ static inline bool isaligned_64(uint64_t x, uint32_t y) return do_div(x, y) == 0; } +/* If @b is a power of 2, return log2(b). Else return -1. */ +static inline int8_t log2_if_power2(unsigned long b) +{ + return is_power_of_2(b) ? ilog2(b) : -1; +} + +/* If @b is a power of 2, return a mask of the lower bits, else return zero. */ +static inline unsigned long long mask64_if_power2(unsigned long b) +{ + return is_power_of_2(b) ? b - 1 : 0; +} + int xfs_rw_bdev(struct block_device *bdev, sector_t sector, unsigned int count, char *data, enum req_op op); diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index 3254ceb71424..6d0d57480577 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -245,6 +245,7 @@ typedef struct xfs_mount { uint8_t m_blkbb_log; /* blocklog - BBSHIFT */ uint8_t m_agno_log; /* log #ag's */ uint8_t m_sectbb_log; /* sectlog - BBSHIFT */ + int8_t m_rtxblklog; /* log2 of rextsize, if possible */ uint m_blockmask; /* sb_blocksize-1 */ uint m_blockwsize; /* sb_blocksize in words */ uint m_blockwmask; /* blockwsize-1 */ @@ -278,6 +279,7 @@ typedef struct xfs_mount { uint64_t m_features; /* active filesystem features */ uint64_t m_low_space[XFS_LOWSP_MAX]; uint64_t m_low_rtexts[XFS_LOWSP_MAX]; + uint64_t m_rtxblkmask; /* rt extent block mask */ struct xfs_ino_geometry m_ino_geo; /* inode geometry */ struct xfs_trans_resv m_resv; /* precomputed res values */ /* low free space thresholds */ diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c index b74ba5e51cf8..3573dfef5dd7 100644 --- a/fs/xfs/xfs_rtalloc.c +++ b/fs/xfs/xfs_rtalloc.c @@ -1052,6 +1052,7 @@ xfs_growfs_rt( * Calculate new sb and mount fields for this round. */ nsbp->sb_rextsize = in->extsize; + nmp->m_rtxblklog = -1; /* don't use shift or masking */ nsbp->sb_rbmblocks = bmbno + 1; nrblocks_step = (bmbno + 1) * NBBY * nsbp->sb_blocksize * nsbp->sb_rextsize; diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 3e81826c9a0a..f39c5daeef86 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -710,6 +710,10 @@ xfs_trans_unreserve_and_mod_sb( mp->m_sb.sb_agcount += tp->t_agcount_delta; mp->m_sb.sb_imax_pct += tp->t_imaxpct_delta; mp->m_sb.sb_rextsize += tp->t_rextsize_delta; + if (tp->t_rextsize_delta) { + mp->m_rtxblklog = log2_if_power2(mp->m_sb.sb_rextsize); + mp->m_rtxblkmask = mask64_if_power2(mp->m_sb.sb_rextsize); + } mp->m_sb.sb_rbmblocks += tp->t_rbmblocks_delta; mp->m_sb.sb_rblocks += tp->t_rblocks_delta; mp->m_sb.sb_rextents += tp->t_rextents_delta; -- cgit v1.2.3