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Fix performance problem of virStorageVolCreateXMLFrom()

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This patch changes zerobuf variable from array to VIR_ALLOC_N().

Signed-off-by: Minoru Usui <usui@mxm.nes.nec.co.jp>
This commit is contained in:
Minoru Usui 2011-03-08 20:06:51 +09:00 committed by Eric Blake
parent e2d24e8de4
commit 9bfde34661
2 changed files with 36 additions and 10 deletions
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AUTHORS
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@ -158,6 +158,7 @@ Patches have also been contributed by:
Markus Groß <gross@univention.de>
Phil Petty <phpetty@cisco.com>
Taku Izumi <izumi.taku@jp.fujitsu.com>
Minoru Usui <usui@mxm.nes.nec.co.jp>
[....send patches to get your name here....]

45
src/storage/storage_backend.c
View File

@ -1,7 +1,7 @@
/*
* storage_backend.c: internal storage driver backend contract
*
* Copyright (C) 2007-2010 Red Hat, Inc.
* Copyright (C) 2007-2011 Red Hat, Inc.
* Copyright (C) 2007-2008 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
@ -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 (4 * 1024)
static int ATTRIBUTE_NONNULL (2)
virStorageBackendCopyToFD(virStorageVolDefPtr vol,
virStorageVolDefPtr inputvol,
@ -119,9 +126,12 @@ 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 = 0;
int interval;
char *zerobuf;
char *buf = NULL;
struct stat st;
if ((inputfd = open(inputvol->target.path, O_RDONLY)) < 0) {
ret = -errno;
@ -131,9 +141,23 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
goto cleanup;
}
bzero(&zerobuf, sizeof(zerobuf));
#ifdef __linux__
if (ioctl(fd, BLKBSZGET, &wbytes) < 0) {
wbytes = 0;
}
#endif
if ((wbytes == 0) && fstat(fd, &st) == 0)
wbytes = st.st_blksize;
if (wbytes < WRITE_BLOCK_SIZE_DEFAULT)
wbytes = WRITE_BLOCK_SIZE_DEFAULT;
if (VIR_ALLOC_N(buf, bytes) < 0) {
if (VIR_ALLOC_N(zerobuf, wbytes) < 0) {
ret = -errno;
virReportOOMError();
goto cleanup;
}
if (VIR_ALLOC_N(buf, rbytes) < 0) {
ret = -errno;
virReportOOMError();
goto cleanup;
@ -144,10 +168,10 @@ 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 +184,7 @@ 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 +203,7 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
goto cleanup;
}
} while ((amtleft -= 512) > 0);
} while ((amtleft -= interval) > 0);
}
if (VIR_CLOSE(inputfd) < 0) {
@ -196,6 +220,7 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
cleanup:
VIR_FORCE_CLOSE(inputfd);
VIR_FREE(zerobuf);
VIR_FREE(buf);
return ret;