qemu-img: open files with cache=writeback

Data integrity is not important in qemu-img, so open the files with
cache=writeback. This fixes the performance regression seen with qemu-img
since revision 5485, and most particularly with the qcow2 format.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5839 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aurel32 2008-11-30 19:12:49 +00:00
parent b8dbdddc9e
commit 137519ce2e

View File

@ -30,6 +30,9 @@
#include <windows.h>
#endif
/* Default to cache=writeback as data integrity is not important for qemu-tcg. */
#define BRDV_O_FLAGS BDRV_O_CACHE_WB
static void __attribute__((noreturn)) error(const char *fmt, ...)
{
va_list ap;
@ -186,7 +189,7 @@ static BlockDriverState *bdrv_new_open(const char *filename,
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, 0, drv) < 0) {
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
if (bdrv_is_encrypted(bs)) {
@ -317,7 +320,7 @@ static int img_commit(int argc, char **argv)
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, 0, drv) < 0) {
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
ret = bdrv_commit(bs);
@ -691,7 +694,7 @@ static int img_info(int argc, char **argv)
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, 0, drv) < 0) {
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
bdrv_get_format(bs, fmt_name, sizeof(fmt_name));