[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 08/16] migration: stop compression to allocate and fr
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[Qemu-devel] [PULL 08/16] migration: stop compression to allocate and free memory frequently |
Date: |
Wed, 25 Apr 2018 21:03:18 +0100 |
From: Xiao Guangrong <address@hidden>
Current code uses compress2() to compress memory which manages memory
internally, that causes huge memory is allocated and freed very
frequently
More worse, frequently returning memory to kernel will flush TLBs
and trigger invalidation callbacks on mmu-notification which
interacts with KVM MMU, that dramatically reduce the performance
of VM
So, we maintain the memory by ourselves and reuse it for each
compression
Reviewed-by: Peter Xu <address@hidden>
Reviewed-by: Jiang Biao <address@hidden>
Signed-off-by: Xiao Guangrong <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
migration/qemu-file.c | 39 ++++++++++++++++++++++++++++++++-------
migration/qemu-file.h | 6 ++++--
migration/ram.c | 41 ++++++++++++++++++++++++++++++++---------
3 files changed, 68 insertions(+), 18 deletions(-)
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index bb63c779cc..bafe3a0c0d 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -658,8 +658,32 @@ uint64_t qemu_get_be64(QEMUFile *f)
return v;
}
-/* Compress size bytes of data start at p with specific compression
- * level and store the compressed data to the buffer of f.
+/* return the size after compression, or negative value on error */
+static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len,
+ const uint8_t *source, size_t source_len)
+{
+ int err;
+
+ err = deflateReset(stream);
+ if (err != Z_OK) {
+ return -1;
+ }
+
+ stream->avail_in = source_len;
+ stream->next_in = (uint8_t *)source;
+ stream->avail_out = dest_len;
+ stream->next_out = dest;
+
+ err = deflate(stream, Z_FINISH);
+ if (err != Z_STREAM_END) {
+ return -1;
+ }
+
+ return stream->next_out - dest;
+}
+
+/* Compress size bytes of data start at p and store the compressed
+ * data to the buffer of f.
*
* When f is not writable, return -1 if f has no space to save the
* compressed data.
@@ -667,9 +691,8 @@ uint64_t qemu_get_be64(QEMUFile *f)
* do fflush first, if f still has no space to save the compressed
* data, return -1.
*/
-
-ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
- int level)
+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);
@@ -683,8 +706,10 @@ ssize_t qemu_put_compression_data(QEMUFile *f, const
uint8_t *p, size_t size,
return -1;
}
}
- if (compress2(f->buf + f->buf_index + sizeof(int32_t), (uLongf *)&blen,
- (Bytef *)p, size, level) != Z_OK) {
+
+ blen = qemu_compress_data(stream, f->buf + f->buf_index + sizeof(int32_t),
+ blen, p, size);
+ if (blen < 0) {
error_report("Compress Failed!");
return 0;
}
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index f4f356ab12..2ccfcfb2a8 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -25,6 +25,8 @@
#ifndef MIGRATION_QEMU_FILE_H
#define MIGRATION_QEMU_FILE_H
+#include <zlib.h>
+
/* Read a chunk of data from a file at the given position. The pos argument
* can be ignored if the file is only be used for streaming. The number of
* bytes actually read should be returned.
@@ -132,8 +134,8 @@ bool qemu_file_is_writable(QEMUFile *f);
size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t
offset);
size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
-ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
- int level);
+ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
+ const uint8_t *p, size_t size);
int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
/*
diff --git a/migration/ram.c b/migration/ram.c
index 409c847a76..a21514a469 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -269,6 +269,7 @@ struct CompressParam {
QemuCond cond;
RAMBlock *block;
ram_addr_t offset;
+ z_stream stream;
};
typedef struct CompressParam CompressParam;
@@ -299,7 +300,7 @@ static QemuThread *decompress_threads;
static QemuMutex decomp_done_lock;
static QemuCond decomp_done_cond;
-static int do_compress_ram_page(QEMUFile *f, RAMBlock *block,
+static int do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
ram_addr_t offset);
static void *do_data_compress(void *opaque)
@@ -316,7 +317,7 @@ static void *do_data_compress(void *opaque)
param->block = NULL;
qemu_mutex_unlock(¶m->mutex);
- do_compress_ram_page(param->file, block, offset);
+ do_compress_ram_page(param->file, ¶m->stream, block, offset);
qemu_mutex_lock(&comp_done_lock);
param->done = true;
@@ -357,10 +358,19 @@ static void compress_threads_save_cleanup(void)
terminate_compression_threads();
thread_count = migrate_compress_threads();
for (i = 0; i < thread_count; i++) {
+ /*
+ * we use it as a indicator which shows if the thread is
+ * properly init'd or not
+ */
+ if (!comp_param[i].file) {
+ break;
+ }
qemu_thread_join(compress_threads + i);
- qemu_fclose(comp_param[i].file);
qemu_mutex_destroy(&comp_param[i].mutex);
qemu_cond_destroy(&comp_param[i].cond);
+ deflateEnd(&comp_param[i].stream);
+ qemu_fclose(comp_param[i].file);
+ comp_param[i].file = NULL;
}
qemu_mutex_destroy(&comp_done_lock);
qemu_cond_destroy(&comp_done_cond);
@@ -370,12 +380,12 @@ static void compress_threads_save_cleanup(void)
comp_param = NULL;
}
-static void compress_threads_save_setup(void)
+static int compress_threads_save_setup(void)
{
int i, thread_count;
if (!migrate_use_compression()) {
- return;
+ return 0;
}
thread_count = migrate_compress_threads();
compress_threads = g_new0(QemuThread, thread_count);
@@ -383,6 +393,11 @@ static void compress_threads_save_setup(void)
qemu_cond_init(&comp_done_cond);
qemu_mutex_init(&comp_done_lock);
for (i = 0; i < thread_count; i++) {
+ if (deflateInit(&comp_param[i].stream,
+ migrate_compress_level()) != Z_OK) {
+ goto exit;
+ }
+
/* comp_param[i].file is just used as a dummy buffer to save data,
* set its ops to empty.
*/
@@ -395,6 +410,11 @@ static void compress_threads_save_setup(void)
do_data_compress, comp_param + i,
QEMU_THREAD_JOINABLE);
}
+ return 0;
+
+exit:
+ compress_threads_save_cleanup();
+ return -1;
}
/* Multiple fd's */
@@ -1031,7 +1051,7 @@ static int ram_save_page(RAMState *rs, PageSearchStatus
*pss, bool last_stage)
return pages;
}
-static int do_compress_ram_page(QEMUFile *f, RAMBlock *block,
+static int do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
ram_addr_t offset)
{
RAMState *rs = ram_state;
@@ -1040,8 +1060,7 @@ static int do_compress_ram_page(QEMUFile *f, RAMBlock
*block,
bytes_sent = save_page_header(rs, f, block, offset |
RAM_SAVE_FLAG_COMPRESS_PAGE);
- blen = qemu_put_compression_data(f, p, TARGET_PAGE_SIZE,
- migrate_compress_level());
+ blen = qemu_put_compression_data(f, stream, p, TARGET_PAGE_SIZE);
if (blen < 0) {
bytes_sent = 0;
qemu_file_set_error(migrate_get_current()->to_dst_file, blen);
@@ -2214,9 +2233,14 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
RAMState **rsp = opaque;
RAMBlock *block;
+ if (compress_threads_save_setup()) {
+ return -1;
+ }
+
/* migration has already setup the bitmap, reuse it. */
if (!migration_in_colo_state()) {
if (ram_init_all(rsp) != 0) {
+ compress_threads_save_cleanup();
return -1;
}
}
@@ -2236,7 +2260,6 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
}
rcu_read_unlock();
- compress_threads_save_setup();
ram_control_before_iterate(f, RAM_CONTROL_SETUP);
ram_control_after_iterate(f, RAM_CONTROL_SETUP);
--
2.17.0
- [Qemu-devel] [PULL 00/16] migration queue, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 04/16] migration: postcopy_blocktime documentation, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 01/16] migration: introduce postcopy-blocktime capability, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 02/16] migration: add postcopy blocktime ctx into MigrationIncomingState, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 05/16] migration: add blocktime calculation into migration-test, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 08/16] migration: stop compression to allocate and free memory frequently,
Dr. David Alan Gilbert (git) <=
- [Qemu-devel] [PULL 07/16] migration: stop compressing page in migration thread, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 09/16] migration: stop decompression to allocate and free memory frequently, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 06/16] migration: add postcopy total blocktime into query-migrate, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 15/16] migration: introduce save_normal_page(), Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 14/16] migration: move calling save_zero_page to the common place, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 03/16] migration: calculate vCPU blocktime on dst side, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 10/16] migration: detect compression and decompression errors, Dr. David Alan Gilbert (git), 2018/04/25
- [Qemu-devel] [PULL 12/16] migration: move some code to ram_save_host_page, Dr. David Alan Gilbert (git), 2018/04/25