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xfs: improve kmem_realloc
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Use krealloc to implement our realloc function.  This helps to avoid
new allocations if we are still in the slab bucket.  At least for the
bmap btree root that's actually the common case.

This also allows removing the now unused oldsize argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Christoph Hellwig authored and Dave Chinner committed Apr 5, 2016
1 parent 9f27889 commit 664b60f
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Showing 5 changed files with 20 additions and 21 deletions.
26 changes: 15 additions & 11 deletions fs/xfs/kmem.c
Original file line number Diff line number Diff line change
Expand Up @@ -93,19 +93,23 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
}

void *
kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
xfs_km_flags_t flags)
kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
{
void *new;
int retries = 0;
gfp_t lflags = kmem_flags_convert(flags);
void *ptr;

new = kmem_alloc(newsize, flags);
if (ptr) {
if (new)
memcpy(new, ptr,
((oldsize < newsize) ? oldsize : newsize));
kmem_free(ptr);
}
return new;
do {
ptr = krealloc(old, newsize, lflags);
if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
return ptr;
if (!(++retries % 100))
xfs_err(NULL,
"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
current->comm, current->pid,
newsize, __func__, lflags);
congestion_wait(BLK_RW_ASYNC, HZ/50);
} while (1);
}

void *
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2 changes: 1 addition & 1 deletion fs/xfs/kmem.h
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,7 @@ kmem_flags_convert(xfs_km_flags_t flags)

extern void *kmem_alloc(size_t, xfs_km_flags_t);
extern void *kmem_zalloc_large(size_t size, xfs_km_flags_t);
extern void *kmem_realloc(const void *, size_t, size_t, xfs_km_flags_t);
extern void *kmem_realloc(const void *, size_t, xfs_km_flags_t);
static inline void kmem_free(const void *ptr)
{
kvfree(ptr);
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10 changes: 3 additions & 7 deletions fs/xfs/libxfs/xfs_inode_fork.c
Original file line number Diff line number Diff line change
Expand Up @@ -516,7 +516,6 @@ xfs_iroot_realloc(
new_max = cur_max + rec_diff;
new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
ifp->if_broot = kmem_realloc(ifp->if_broot, new_size,
XFS_BMAP_BROOT_SPACE_CALC(mp, cur_max),
KM_SLEEP | KM_NOFS);
op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
ifp->if_broot_bytes);
Expand Down Expand Up @@ -660,7 +659,6 @@ xfs_idata_realloc(
ifp->if_u1.if_data =
kmem_realloc(ifp->if_u1.if_data,
real_size,
ifp->if_real_bytes,
KM_SLEEP | KM_NOFS);
}
} else {
Expand Down Expand Up @@ -1376,8 +1374,7 @@ xfs_iext_realloc_direct(
if (rnew_size != ifp->if_real_bytes) {
ifp->if_u1.if_extents =
kmem_realloc(ifp->if_u1.if_extents,
rnew_size,
ifp->if_real_bytes, KM_NOFS);
rnew_size, KM_NOFS);
}
if (rnew_size > ifp->if_real_bytes) {
memset(&ifp->if_u1.if_extents[ifp->if_bytes /
Expand Down Expand Up @@ -1461,9 +1458,8 @@ xfs_iext_realloc_indirect(
if (new_size == 0) {
xfs_iext_destroy(ifp);
} else {
ifp->if_u1.if_ext_irec = (xfs_ext_irec_t *)
kmem_realloc(ifp->if_u1.if_ext_irec,
new_size, size, KM_NOFS);
ifp->if_u1.if_ext_irec =
kmem_realloc(ifp->if_u1.if_ext_irec, new_size, KM_NOFS);
}
}

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2 changes: 1 addition & 1 deletion fs/xfs/xfs_log_recover.c
Original file line number Diff line number Diff line change
Expand Up @@ -3843,7 +3843,7 @@ xlog_recover_add_to_cont_trans(
old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
old_len = item->ri_buf[item->ri_cnt-1].i_len;

ptr = kmem_realloc(old_ptr, len+old_len, old_len, KM_SLEEP);
ptr = kmem_realloc(old_ptr, len + old_len, KM_SLEEP);
memcpy(&ptr[old_len], dp, len);
item->ri_buf[item->ri_cnt-1].i_len += len;
item->ri_buf[item->ri_cnt-1].i_addr = ptr;
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1 change: 0 additions & 1 deletion fs/xfs/xfs_mount.c
Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,6 @@ xfs_uuid_mount(
if (hole < 0) {
xfs_uuid_table = kmem_realloc(xfs_uuid_table,
(xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
xfs_uuid_table_size * sizeof(*xfs_uuid_table),
KM_SLEEP);
hole = xfs_uuid_table_size++;
}
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