pve-qemu/debian/patches/pve/0018-PVE-add-optional-buffe...

188 lines
6.4 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Mon, 4 May 2020 11:05:08 +0200
Subject: [PATCH] PVE: add optional buffer size to QEMUFile
So we can use a 4M buffer for savevm-async which should
increase performance storing the state onto ceph.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
[increase max IOV count in QEMUFile to actually write more data]
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
---
migration/qemu-file.c | 38 +++++++++++++++++++++++++-------------
migration/qemu-file.h | 1 +
migration/savevm-async.c | 4 ++--
3 files changed, 28 insertions(+), 15 deletions(-)
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index be21518c57..1926b5202c 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -30,8 +30,8 @@
#include "trace.h"
#include "qapi/error.h"
-#define IO_BUF_SIZE 32768
-#define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 64)
+#define DEFAULT_IO_BUF_SIZE 32768
+#define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 256)
struct QEMUFile {
const QEMUFileOps *ops;
@@ -45,7 +45,8 @@ struct QEMUFile {
when reading */
int buf_index;
int buf_size; /* 0 when writing */
- uint8_t buf[IO_BUF_SIZE];
+ size_t buf_allocated_size;
+ uint8_t *buf;
DECLARE_BITMAP(may_free, MAX_IOV_SIZE);
struct iovec iov[MAX_IOV_SIZE];
@@ -101,7 +102,7 @@ bool qemu_file_mode_is_not_valid(const char *mode)
return false;
}
-QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
+QEMUFile *qemu_fopen_ops_sized(void *opaque, const QEMUFileOps *ops, size_t buffer_size)
{
QEMUFile *f;
@@ -109,9 +110,17 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
f->opaque = opaque;
f->ops = ops;
+ f->buf_allocated_size = buffer_size;
+ f->buf = malloc(buffer_size);
+
return f;
}
+QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
+{
+ return qemu_fopen_ops_sized(opaque, ops, DEFAULT_IO_BUF_SIZE);
+}
+
void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks)
{
@@ -346,7 +355,7 @@ static ssize_t qemu_fill_buffer(QEMUFile *f)
}
len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos,
- IO_BUF_SIZE - pending, &local_error);
+ f->buf_allocated_size - pending, &local_error);
if (len > 0) {
f->buf_size += len;
f->pos += len;
@@ -386,6 +395,9 @@ int qemu_fclose(QEMUFile *f)
ret = ret2;
}
}
+
+ free(f->buf);
+
/* If any error was spotted before closing, we should report it
* instead of the close() return value.
*/
@@ -435,7 +447,7 @@ static void add_buf_to_iovec(QEMUFile *f, size_t len)
{
if (!add_to_iovec(f, f->buf + f->buf_index, len, false)) {
f->buf_index += len;
- if (f->buf_index == IO_BUF_SIZE) {
+ if (f->buf_index == f->buf_allocated_size) {
qemu_fflush(f);
}
}
@@ -461,7 +473,7 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size)
}
while (size > 0) {
- l = IO_BUF_SIZE - f->buf_index;
+ l = f->buf_allocated_size - f->buf_index;
if (l > size) {
l = size;
}
@@ -508,8 +520,8 @@ size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset)
size_t index;
assert(!qemu_file_is_writable(f));
- assert(offset < IO_BUF_SIZE);
- assert(size <= IO_BUF_SIZE - offset);
+ assert(offset < f->buf_allocated_size);
+ assert(size <= f->buf_allocated_size - offset);
/* The 1st byte to read from */
index = f->buf_index + offset;
@@ -559,7 +571,7 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size)
size_t res;
uint8_t *src;
- res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0);
+ res = qemu_peek_buffer(f, &src, MIN(pending, f->buf_allocated_size), 0);
if (res == 0) {
return done;
}
@@ -593,7 +605,7 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size)
*/
size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
{
- if (size < IO_BUF_SIZE) {
+ if (size < f->buf_allocated_size) {
size_t res;
uint8_t *src;
@@ -618,7 +630,7 @@ int qemu_peek_byte(QEMUFile *f, int offset)
int index = f->buf_index + offset;
assert(!qemu_file_is_writable(f));
- assert(offset < IO_BUF_SIZE);
+ assert(offset < f->buf_allocated_size);
if (index >= f->buf_size) {
qemu_fill_buffer(f);
@@ -770,7 +782,7 @@ static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len,
ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
const uint8_t *p, size_t size)
{
- ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
+ ssize_t blen = f->buf_allocated_size - f->buf_index - sizeof(int32_t);
if (blen < compressBound(size)) {
return -1;
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index a9b6d6ccb7..8752d27c74 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -120,6 +120,7 @@ typedef struct QEMUFileHooks {
} QEMUFileHooks;
QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
+QEMUFile *qemu_fopen_ops_sized(void *opaque, const QEMUFileOps *ops, size_t buffer_size);
void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
int qemu_get_fd(QEMUFile *f);
int qemu_fclose(QEMUFile *f);
diff --git a/migration/savevm-async.c b/migration/savevm-async.c
index 4e345c1a7d..8a17ec1f74 100644
--- a/migration/savevm-async.c
+++ b/migration/savevm-async.c
@@ -414,7 +414,7 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
goto restart;
}
- snap_state.file = qemu_fopen_ops(&snap_state, &block_file_ops);
+ snap_state.file = qemu_fopen_ops_sized(&snap_state, &block_file_ops, 4 * 1024 * 1024);
if (!snap_state.file) {
error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
@@ -563,7 +563,7 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
blk_op_block_all(be, blocker);
/* restore the VM state */
- f = qemu_fopen_ops(be, &loadstate_file_ops);
+ f = qemu_fopen_ops_sized(be, &loadstate_file_ops, 4 * 1024 * 1024);
if (!f) {
error_setg(errp, "Could not open VM state file");
goto the_end;