From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 02 Oct 2007 01:11:10 -0700 (PDT) Received: from mx2.suse.de (ns2.suse.de [195.135.220.15]) by oss.sgi.com (8.12.11.20060308/8.12.10/SuSE Linux 0.7) with ESMTP id l928B1qT016937 for ; Tue, 2 Oct 2007 01:11:04 -0700 Received: from Relay2.suse.de (mail2.suse.de [195.135.221.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id C3C8522EBE for ; Tue, 2 Oct 2007 10:11:01 +0200 (CEST) From: Andi Kleen Subject: [PATCH] Replace XFS bit functions with Linux functions Date: Tue, 2 Oct 2007 10:10:58 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200710021010.58284.ak@suse.de> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: xfs@oss.sgi.com XFS had some own functions to find high and low bits. This patch replaces them with a call to the respective Linux functions. The semantics of the Linux functions differ a little, but i checked all call sites that they can deal with that. I think all callers are ok; but i added a few more asserts for the 0 case (where Linux and old XFS differ) just to make it easy to detect mistakes. The resulting xfs.ko is about 500 bytes smaller on x86-64 This is similar to the patch Eric sent some days ago, but does it more efficiently imho. It replaces his patch. I wasn't able to do a full XFS QA run over this unfortunately; but did careful review. Signed-off-by: Andi Kleen Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_bit.c =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_bit.c +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_bit.c @@ -22,112 +22,9 @@ #include "xfs_buf_item.h" /* - * XFS bit manipulation routines, used in non-realtime code. + * XFS bit manipulation routines */ -#ifndef HAVE_ARCH_HIGHBIT -/* - * Index of high bit number in byte, -1 for none set, 0..7 otherwise. - */ -static const char xfs_highbit[256] = { - -1, 0, 1, 1, 2, 2, 2, 2, /* 00 .. 07 */ - 3, 3, 3, 3, 3, 3, 3, 3, /* 08 .. 0f */ - 4, 4, 4, 4, 4, 4, 4, 4, /* 10 .. 17 */ - 4, 4, 4, 4, 4, 4, 4, 4, /* 18 .. 1f */ - 5, 5, 5, 5, 5, 5, 5, 5, /* 20 .. 27 */ - 5, 5, 5, 5, 5, 5, 5, 5, /* 28 .. 2f */ - 5, 5, 5, 5, 5, 5, 5, 5, /* 30 .. 37 */ - 5, 5, 5, 5, 5, 5, 5, 5, /* 38 .. 3f */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 40 .. 47 */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 48 .. 4f */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 50 .. 57 */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 58 .. 5f */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 60 .. 67 */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 68 .. 6f */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 70 .. 77 */ - 6, 6, 6, 6, 6, 6, 6, 6, /* 78 .. 7f */ - 7, 7, 7, 7, 7, 7, 7, 7, /* 80 .. 87 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* 88 .. 8f */ - 7, 7, 7, 7, 7, 7, 7, 7, /* 90 .. 97 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* 98 .. 9f */ - 7, 7, 7, 7, 7, 7, 7, 7, /* a0 .. a7 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* a8 .. af */ - 7, 7, 7, 7, 7, 7, 7, 7, /* b0 .. b7 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* b8 .. bf */ - 7, 7, 7, 7, 7, 7, 7, 7, /* c0 .. c7 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* c8 .. cf */ - 7, 7, 7, 7, 7, 7, 7, 7, /* d0 .. d7 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* d8 .. df */ - 7, 7, 7, 7, 7, 7, 7, 7, /* e0 .. e7 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* e8 .. ef */ - 7, 7, 7, 7, 7, 7, 7, 7, /* f0 .. f7 */ - 7, 7, 7, 7, 7, 7, 7, 7, /* f8 .. ff */ -}; -#endif - -/* - * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set. - */ -inline int -xfs_highbit32( - __uint32_t v) -{ -#ifdef HAVE_ARCH_HIGHBIT - return highbit32(v); -#else - int i; - - if (v & 0xffff0000) - if (v & 0xff000000) - i = 24; - else - i = 16; - else if (v & 0x0000ffff) - if (v & 0x0000ff00) - i = 8; - else - i = 0; - else - return -1; - return i + xfs_highbit[(v >> i) & 0xff]; -#endif -} - -/* - * xfs_lowbit64: get low bit set out of 64-bit argument, -1 if none set. - */ -int -xfs_lowbit64( - __uint64_t v) -{ - __uint32_t w = (__uint32_t)v; - int n = 0; - - if (w) { /* lower bits */ - n = ffs(w); - } else { /* upper bits */ - w = (__uint32_t)(v >> 32); - if (w && (n = ffs(w))) - n += 32; - } - return n - 1; -} - -/* - * xfs_highbit64: get high bit set out of 64-bit argument, -1 if none set. - */ -int -xfs_highbit64( - __uint64_t v) -{ - __uint32_t h = (__uint32_t)(v >> 32); - - if (h) - return xfs_highbit32(h) + 32; - return xfs_highbit32((__uint32_t)v); -} - - /* * Return whether bitmap is empty. * Size is number of words in the bitmap, which is padded to word boundary Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_bit.h =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_bit.h +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_bit.h @@ -46,15 +46,6 @@ static inline __uint64_t xfs_mask64lo(in return ((__uint64_t)1 << (n)) - 1; } -/* Get high bit set out of 32-bit argument, -1 if none set */ -extern int xfs_highbit32(__uint32_t v); - -/* Get low bit set out of 64-bit argument, -1 if none set */ -extern int xfs_lowbit64(__uint64_t v); - -/* Get high bit set out of 64-bit argument, -1 if none set */ -extern int xfs_highbit64(__uint64_t); - /* Return whether bitmap is empty (1 == empty) */ extern int xfs_bitmap_empty(uint *map, uint size); Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_iget.c =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_iget.c +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_iget.c @@ -55,8 +55,7 @@ xfs_ihash_init(xfs_mount_t *mp) if (!mp->m_ihsize) { icount = mp->m_maxicount ? mp->m_maxicount : (mp->m_sb.sb_dblocks << mp->m_sb.sb_inopblog); - mp->m_ihsize = 1 << max_t(uint, 8, - (xfs_highbit64(icount) + 1) / 2); + mp->m_ihsize = 1 << max_t(uint, 8, fls64(icount) / 2); mp->m_ihsize = min_t(uint, mp->m_ihsize, (64 * NBPP) / sizeof(xfs_ihash_t)); } Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_mount.c =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_mount.c +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_mount.c @@ -439,7 +439,7 @@ xfs_xlatesb( mem_ptr = (xfs_caddr_t)sb; while (fields) { - f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields); + f = (xfs_sb_field_t)find_first_bit((unsigned long *)&fields,64); first = xfs_sb_info[f].offset; size = xfs_sb_info[f + 1].offset - first; @@ -589,7 +589,7 @@ xfs_mount_common(xfs_mount_t *mp, xfs_sb mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG; mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT; mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT; - mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1; + mp->m_agno_log = fls(sbp->sb_agcount - 1); mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog; mp->m_litino = sbp->sb_inodesize - ((uint)sizeof(xfs_dinode_core_t) + (uint)sizeof(xfs_agino_t)); @@ -1428,11 +1428,11 @@ xfs_mod_sb(xfs_trans_t *tp, __int64_t fi /* find modified range */ - f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields); + f = (xfs_sb_field_t)find_first_bit((unsigned long *)&fields, 64); ASSERT((1LL << f) & XFS_SB_MOD_BITS); first = xfs_sb_info[f].offset; - f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields); + f = (xfs_sb_field_t)fls64((__uint64_t)fields) - 1; ASSERT((1LL << f) & XFS_SB_MOD_BITS); last = xfs_sb_info[f + 1].offset - 1; Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_rtalloc.h =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_rtalloc.h +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_rtalloc.h @@ -60,13 +60,19 @@ struct xfs_trans; #define XFS_RTMIN(a,b) ((a) < (b) ? (a) : (b)) #define XFS_RTMAX(a,b) ((a) > (b) ? (a) : (b)) -#define XFS_RTLOBIT(w) xfs_lowbit32(w) -#define XFS_RTHIBIT(w) xfs_highbit32(w) +/* All callers check for 0 arguments already; so no -1 handling */ +static inline int xfs_rtlobit(unsigned long v) +{ + return find_first_bit(&v, 32); +} + +#define XFS_RTLOBIT(w) xfs_rtlobit(w) +#define XFS_RTHIBIT(w) (fls(w) - 1) #if XFS_BIG_BLKNOS -#define XFS_RTBLOCKLOG(b) xfs_highbit64(b) +#define XFS_RTBLOCKLOG(b) (fls64(b) - 1) #else -#define XFS_RTBLOCKLOG(b) xfs_highbit32(b) +#define XFS_RTBLOCKLOG(b) (fls(b) - 1) #endif Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_rtalloc.c =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_rtalloc.c +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_rtalloc.c @@ -73,18 +73,6 @@ STATIC int xfs_rtmodify_summary(xfs_moun */ /* - * xfs_lowbit32: get low bit set out of 32-bit argument, -1 if none set. - */ -STATIC int -xfs_lowbit32( - __uint32_t v) -{ - if (v) - return ffs(v) - 1; - return -1; -} - -/* * Allocate space to the bitmap or summary file, and zero it, for growfs. */ STATIC int /* error */ @@ -444,7 +432,8 @@ xfs_rtallocate_extent_near( } bbno = XFS_BITTOBLOCK(mp, bno); i = 0; - log2len = xfs_highbit32(minlen); + ASSERT(minlen != 0); + log2len = fls(minlen) - 1; /* * Loop over all bitmap blocks (bbno + i is current block). */ @@ -607,11 +596,13 @@ xfs_rtallocate_extent_size( int error; /* error value */ int i; /* bitmap block number */ int l; /* level number (loop control) */ + int end; xfs_rtblock_t n; /* next block to be tried */ xfs_rtblock_t r; /* result block number */ xfs_suminfo_t sum; /* summary information for extents */ ASSERT(minlen % prod == 0 && maxlen % prod == 0); + ASSERT(maxlen != 0); /* * Loop over all the levels starting with maxlen. * At each level, look at all the bitmap blocks, to see if there @@ -619,7 +610,7 @@ xfs_rtallocate_extent_size( * Note, only on the initial level can the allocation fail if * the summary says there's an extent. */ - for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) { + for (l = fls(maxlen) - 1; l < mp->m_rsumlevels; l++) { /* * Loop over all the bitmap blocks. */ @@ -669,12 +660,15 @@ xfs_rtallocate_extent_size( *rtblock = NULLRTBLOCK; return 0; } + ASSERT(maxlen != 0); + ASSERT(minlen != 0); /* * Loop over sizes, from maxlen down to minlen. * This time, when we do the allocations, allow smaller ones * to succeed. */ - for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) { + end = fls(minlen) - 1; + for (l = fls(maxlen) - 1; l >= end; l--) { /* * Loop over all the bitmap blocks, try an allocation * starting in that block. @@ -1863,7 +1857,6 @@ xfs_growfs_rt( xfs_drfsbno_t nrblocks; /* new number of realtime blocks */ xfs_extlen_t nrbmblocks; /* new number of rt bitmap blocks */ xfs_drtbno_t nrextents; /* new number of realtime extents */ - uint8_t nrextslog; /* new log2 of sb_rextents */ xfs_extlen_t nrsumblocks; /* new number of summary blocks */ uint nrsumlevels; /* new rt summary levels */ uint nrsumsize; /* new size of rt summary, bytes */ @@ -1900,8 +1893,7 @@ xfs_growfs_rt( nrextents = nrblocks; do_div(nrextents, in->extsize); nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize); - nrextslog = xfs_highbit32(nrextents); - nrsumlevels = nrextslog + 1; + nrsumlevels = fls(nrextents); nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks; nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize); nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks); @@ -1954,7 +1946,8 @@ xfs_growfs_rt( nsbp->sb_blocksize * nsbp->sb_rextsize); nsbp->sb_rextents = nsbp->sb_rblocks; do_div(nsbp->sb_rextents, nsbp->sb_rextsize); - nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents); + ASSERT(nsbp->sb_rextents != 0); + nsbp->sb_rextslog = fls(nsbp->sb_rextents) - 1; nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1; nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * @@ -2317,9 +2310,10 @@ xfs_rtpick_extent( *seqp = 0; } seq = *seqp; - if ((log2 = xfs_highbit64(seq)) == -1) + if ((log2 = fls64(seq)) == 0) b = 0; else { + log2--; resid = seq - (1ULL << log2); b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >> (log2 + 1); Index: linux-2.6.23-rc8-misc/fs/xfs/xfs_ialloc.h =================================================================== --- linux-2.6.23-rc8-misc.orig/fs/xfs/xfs_ialloc.h +++ linux-2.6.23-rc8-misc/fs/xfs/xfs_ialloc.h @@ -57,10 +57,10 @@ xfs_make_iptr(struct xfs_mount *mp, stru #define XFS_IALLOC_FIND_FREE(fp) xfs_ialloc_find_free(fp) static inline int xfs_ialloc_find_free(xfs_inofree_t *fp) { - return xfs_lowbit64(*fp); + unsigned long v = *fp; /* Guarantee alignment */ + return find_first_bit(&v, 64); } - #ifdef __KERNEL__ /* * Allocate an inode on disk.