[libvirt] [PATCH v2] Fix performance problem of virStorageVolCreateXMLFrom()
This patch changes zerobuf variable from array to VIR_ALLOC_N().
Signed-off-by: Minoru Usui <usui(a)mxm.nes.nec.co.jp>
---
src/storage/storage_backend.c | 38 +++++++++++++++++++++++++++++---------
1 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index 2eede74..3a22da4 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -36,6 +36,10 @@
#include <sys/stat.h>
#include <sys/param.h>
#include <dirent.h>
+#ifdef __linux__
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+#endif
#if HAVE_SELINUX
# include <selinux/selinux.h>
@@ -108,6 +112,9 @@ enum {
TOOL_QCOW_CREATE,
};
+#define READ_BLOCK_SIZE_DEFAULT (1024 * 1024)
+#define WRITE_BLOCK_SIZE_DEFAULT (512)
+
static int ATTRIBUTE_NONNULL (2)
virStorageBackendCopyToFD(virStorageVolDefPtr vol,
virStorageVolDefPtr inputvol,
@@ -119,8 +126,10 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
int amtread = -1;
int ret = 0;
unsigned long long remain;
- size_t bytes = 1024 * 1024;
- char zerobuf[512];
+ size_t rbytes = READ_BLOCK_SIZE_DEFAULT;
+ size_t wbytes = WRITE_BLOCK_SIZE_DEFAULT;
+ int interval;
+ char *zerobuf;
char *buf = NULL;
if ((inputfd = open(inputvol->target.path, O_RDONLY)) < 0) {
@@ -131,9 +140,19 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
goto cleanup;
}
- bzero(&zerobuf, sizeof(zerobuf));
+#ifdef __linux__
+ if (ioctl(fd, BLKBSZGET, &wbytes) < 0) {
+ wbytes = WRITE_BLOCK_SIZE_DEFAULT;
+ }
+#endif
+
+ if (VIR_ALLOC_N(zerobuf, wbytes) < 0) {
+ ret = -errno;
+ virReportOOMError();
+ goto cleanup;
+ }
- if (VIR_ALLOC_N(buf, bytes) < 0) {
+ if (VIR_ALLOC_N(buf, rbytes) < 0) {
ret = -errno;
virReportOOMError();
goto cleanup;
@@ -144,10 +163,10 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
while (amtread != 0) {
int amtleft;
- if (remain < bytes)
- bytes = remain;
+ if (remain < rbytes)
+ rbytes = remain;
- if ((amtread = saferead(inputfd, buf, bytes)) < 0) {
+ if ((amtread = saferead(inputfd, buf, rbytes)) < 0) {
ret = -errno;
virReportSystemError(errno,
_("failed reading from file '%s'"),
@@ -160,7 +179,7 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
* blocks */
amtleft = amtread;
do {
- int interval = ((512 > amtleft) ? amtleft : 512);
+ interval = ((wbytes > amtleft) ? amtleft : wbytes);
int offset = amtread - amtleft;
if (is_dest_file && memcmp(buf+offset, zerobuf, interval) == 0) {
@@ -179,7 +198,7 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
goto cleanup;
}
- } while ((amtleft -= 512) > 0);
+ } while ((amtleft -= interval) > 0);
}
if (VIR_CLOSE(inputfd) < 0) {
@@ -196,6 +215,7 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
cleanup:
VIR_FORCE_CLOSE(inputfd);
+ VIR_FREE(zerobuf);
VIR_FREE(buf);
return ret;
--
Minoru Usui <usui(a)mxm.nes.nec.co.jp>