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author | Jan Beulich <jbeulich@suse.com> | 2011-10-13 10:03:43 +0200 |
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committer | Jan Beulich <jbeulich@suse.com> | 2011-10-13 10:03:43 +0200 |
commit | b829a0ff5794ee5b0f96a0c872f6a4ed7b1007c7 (patch) | |
tree | 0f86021d74a5fc61fc0badd2c142d64cb90ba396 /xen/common/xmalloc_tlsf.c | |
parent | ddbb942359ebec0d96a73a90495e0b29a19266f9 (diff) | |
download | xen-b829a0ff5794ee5b0f96a0c872f6a4ed7b1007c7.tar.gz xen-b829a0ff5794ee5b0f96a0c872f6a4ed7b1007c7.tar.bz2 xen-b829a0ff5794ee5b0f96a0c872f6a4ed7b1007c7.zip |
xmalloc: return unused full pages on multi-page allocations
Certain (boot time) allocations are relatively large (particularly when
building with high NR_CPUS), but can also happen to be pretty far away
from a power-of-two size. Utilize the page allocator's (other than
Linux'es) capability of allowing to return space from higher-order
allocations in smaller pieces to return the unused parts immediately.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/common/xmalloc_tlsf.c')
-rw-r--r-- | xen/common/xmalloc_tlsf.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/xen/common/xmalloc_tlsf.c b/xen/common/xmalloc_tlsf.c index 8a82355e09..3235af117c 100644 --- a/xen/common/xmalloc_tlsf.c +++ b/xen/common/xmalloc_tlsf.c @@ -527,13 +527,21 @@ static void xmalloc_pool_put(void *p) static void *xmalloc_whole_pages(unsigned long size) { struct bhdr *b; - unsigned int pageorder = get_order_from_bytes(size + BHDR_OVERHEAD); + unsigned int i, pageorder = get_order_from_bytes(size + BHDR_OVERHEAD); + char *p; b = alloc_xenheap_pages(pageorder, 0); if ( b == NULL ) return NULL; - b->size = (1 << (pageorder + PAGE_SHIFT)); + b->size = PAGE_ALIGN(size + BHDR_OVERHEAD); + for ( p = (char *)b + b->size, i = 0; i < pageorder; ++i ) + if ( (unsigned long)p & (PAGE_SIZE << i) ) + { + free_xenheap_pages(p, i); + p += PAGE_SIZE << i; + } + return (void *)b->ptr.buffer; } @@ -611,7 +619,20 @@ void xfree(void *p) } if ( b->size >= PAGE_SIZE ) - free_xenheap_pages((void *)b, get_order_from_bytes(b->size)); + { + unsigned int i, order = get_order_from_bytes(b->size); + + BUG_ON((unsigned long)b & ((PAGE_SIZE << order) - 1)); + for ( i = 0; ; ++i ) + { + if ( !(b->size & (PAGE_SIZE << i)) ) + continue; + b->size -= PAGE_SIZE << i; + free_xenheap_pages((void *)b + b->size, i); + if ( i + 1 >= order ) + break; + } + } else xmem_pool_free(p, xenpool); } |