Minimise the stack overhead of the remaining stack variables and
structures placed on the stack by packing them without holes. pahole
is used to optimise allocation args structures, stack variables are
done manually.
[hch: various updates while forward porting the changes]
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: xfs/fs/xfs/xfs_bmap.h
===================================================================
--- xfs.orig/fs/xfs/xfs_bmap.h 2011-09-11 08:46:48.000000000 -0400
+++ xfs/fs/xfs/xfs_bmap.h 2011-09-11 09:06:45.279781419 -0400
@@ -118,6 +118,7 @@ typedef struct xfs_bmalloca {
xfs_fileoff_t offset; /* offset in file filling in */
xfs_extlen_t length; /* i/o length asked/allocated */
+ xfs_extlen_t total; /* total blocks needed for xaction */
xfs_fsblock_t blkno; /* starting block of new extent */
struct xfs_btree_cur *cur; /* btree cursor */
@@ -125,14 +126,13 @@ typedef struct xfs_bmalloca {
int nallocs;/* number of extents alloc'd */
int logflags;/* flags for transaction logging */
- xfs_extlen_t total; /* total blocks needed for xaction */
xfs_extlen_t minlen; /* minimum allocation size (blocks) */
- xfs_extlen_t minleft; /* amount must be left after alloc */
- char eof; /* set if allocating past last extent */
- char wasdel; /* replacing a delayed allocation */
- char userdata;/* set if is user data */
- char aeof; /* allocated space at eof */
- char conv; /* overwriting unwritten extents */
+ xfs_extlen_t minleft;/* amount must be left after alloc */
+ unsigned int eof : 1;/* set if allocating past last extent */
+ unsigned int wasdel : 1; /* replacing a delayed allocation */
+ unsigned int userdata : 1;/* set if is user data */
+ unsigned int aeof : 1;/* allocated space at eof */
+ unsigned int conv : 1;/* overwriting unwritten extents */
} xfs_bmalloca_t;
/*
Index: xfs/fs/xfs/xfs_bmap.c
===================================================================
--- xfs.orig/fs/xfs/xfs_bmap.c 2011-09-11 08:47:11.743121736 -0400
+++ xfs/fs/xfs/xfs_bmap.c 2011-09-11 09:05:37.706448434 -0400
@@ -2359,11 +2359,11 @@ xfs_bmap_btalloc(
xfs_bmalloca_t *ap) /* bmap alloc argument struct */
{
xfs_mount_t *mp; /* mount point structure */
+ xfs_alloc_arg_t args;
xfs_alloctype_t atype = 0; /* type for allocation routines */
xfs_extlen_t align; /* minimum allocation alignment */
xfs_agnumber_t fb_agno; /* ag number of ap->firstblock */
xfs_agnumber_t ag;
- xfs_alloc_arg_t args;
xfs_extlen_t blen;
xfs_extlen_t nextminlen = 0;
int nullfb; /* true if ap->firstblock isn't set */
@@ -4813,30 +4813,19 @@ xfs_bmapi_write(
int *nmap, /* i/o: mval size/count */
struct xfs_bmap_free *flist) /* i/o: list extents to free */
{
+ struct xfs_bmalloca bma = { 0 }; /* args for xfs_bmap_alloc */
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp;
- struct xfs_bmalloca bma = { 0 }; /* args for xfs_bmap_alloc */
xfs_fileoff_t end; /* end of mapped file region */
- int eof; /* after the end of extents */
- int error; /* error return */
- int n; /* current extent index */
xfs_fileoff_t obno; /* old block number (offset) */
+ int error; /* error return */
+ int n = 0; /* current extent index */
int whichfork; /* data or attr fork */
- char inhole; /* current location is hole in file */
- char wasdelay; /* old extent was delayed */
-
#ifdef DEBUG
- xfs_fileoff_t orig_bno; /* original block number value */
- int orig_flags; /* original flags arg value */
- xfs_filblks_t orig_len; /* original value of len arg */
- struct xfs_bmbt_irec *orig_mval; /* original value of mval */
- int orig_nmap; /* original value of *nmap */
-
- orig_bno = bno;
- orig_len = len;
- orig_flags = flags;
- orig_mval = mval;
- orig_nmap = *nmap;
+ xfs_fileoff_t orig_bno = bno;
+ xfs_filblks_t orig_len = len;
+ struct xfs_bmbt_irec *orig_mval = mval;
+ int orig_nmap = *nmap;
#endif
ASSERT(*nmap >= 1);
@@ -4887,11 +4876,9 @@ xfs_bmapi_write(
goto error0;
}
- xfs_bmap_search_extents(ip, bno, whichfork, &eof, &bma.idx, &bma.got,
+ /* we abuse n as a local variable for eof, as bma.eof is a bitfield */
+ xfs_bmap_search_extents(ip, bno, whichfork, &n, &bma.idx, &bma.got,
&bma.prev);
- n = 0;
- end = bno + len;
- obno = bno;
bma.tp = tp;
bma.ip = ip;
@@ -4899,19 +4886,21 @@ xfs_bmapi_write(
bma.userdata = 0;
bma.flist = flist;
bma.firstblock = firstblock;
+ bma.eof = n;
+ bma.conv = !!(flags & XFS_BMAPI_CONVERT);
+ n = 0;
+ end = bno + len;
+ obno = bno;
while (bno < end && n < *nmap) {
- inhole = eof || bma.got.br_startoff > bno;
- wasdelay = !inhole && isnullstartblock(bma.got.br_startblock);
-
/*
- * First, deal with the hole before the allocated space
- * that we found, if any.
+ * If we are past EOF, in a hole in a delayed allocation call
+ * the allocator to get us a real allocation first.
*/
- if (inhole || wasdelay) {
- bma.eof = eof;
- bma.conv = !!(flags & XFS_BMAPI_CONVERT);
- bma.wasdel = wasdelay;
+ if (bma.eof || bma.got.br_startoff > bno ||
+ isnullstartblock(bma.got.br_startblock)) {
+ bma.wasdel = isnullstartblock(bma.got.br_startblock) &&
+ !bma.eof && bma.got.br_startoff <= bno;
bma.length = len;
bma.offset = bno;
@@ -4950,7 +4939,7 @@ xfs_bmapi_write(
xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma.idx),
&bma.got);
} else
- eof = 1;
+ bma.eof = 1;
}
*nmap = n;
@@ -5008,7 +4997,7 @@ error0:
error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
}
if (!error)
- xfs_bmap_validate_ret(orig_bno, orig_len, orig_flags, orig_mval,
+ xfs_bmap_validate_ret(orig_bno, orig_len, flags, orig_mval,
orig_nmap, *nmap);
return error;
}
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