This looks to be a reasonably common case (many of the previous
callers to xc_map_foreign_pages use it) and it is easy enough to avoid
a malloc for it.
Signed-off-by: Ian Campbell <ian.campb...@citrix.com>
---
v6: New
I'm not 100% sure this is worth the complexity, hence not folding
into the base patch yet, it could easily be dropped.
---
tools/libs/foreignmemory/core.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/tools/libs/foreignmemory/core.c b/tools/libs/foreignmemory/core.c
index 738bb45..26c131b 100644
--- a/tools/libs/foreignmemory/core.c
+++ b/tools/libs/foreignmemory/core.c
@@ -14,6 +14,7 @@
*/
#include <stdlib.h>
+#include <stdbool.h>
#include <assert.h>
#include <errno.h>
@@ -68,14 +69,26 @@ void *xenforeignmemory_map(xenforeignmemory_handle *fmem,
const xen_pfn_t arr[/*num*/], int err[/*num*/])
{
void *ret;
- int *err_to_free = NULL;
+ bool check_errs = false;
+ int single_err, *err_to_free = NULL;
if ( err == NULL )
- err = err_to_free = malloc(num * sizeof(int));
+ {
+ /* singleton case is common enough to be worth short circuiting */
+ if ( num == 1 )
+ err = &single_err;
+ else
+ err = err_to_free = malloc(num * sizeof(int));
+
+ if ( !err )
+ return NULL;
+
+ check_errs = true;
+ }
ret = osdep_xenforeignmemory_map(fmem, dom, prot, num, arr, err);
- if ( ret == 0 && err_to_free )
+ if ( ret == 0 && check_errs )
{
int i;
--
2.1.4
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