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author | Liang Li <liang.z.li@intel.com> | 2016-05-05 15:32:58 +0800 |
---|---|---|
committer | Amit Shah <amit.shah@redhat.com> | 2016-06-17 18:24:28 +0530 |
commit | 33d151f4188a40faee224aba1c7b9ad7b1568eb4 (patch) | |
tree | edbc20b665ca6054ac57c9ebcff9507ce04f5244 /migration | |
parent | a7a9a88f9d29da125b0958f3bd1b15182dc94f5f (diff) | |
download | qemu-33d151f4188a40faee224aba1c7b9ad7b1568eb4.zip qemu-33d151f4188a40faee224aba1c7b9ad7b1568eb4.tar.gz qemu-33d151f4188a40faee224aba1c7b9ad7b1568eb4.tar.bz2 |
migration: refine the decompression code
The current code for multi-thread decompression is not clear,
especially in the aspect of using lock. Refine the code
to make it clear.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Message-Id: <1462433579-13691-9-git-send-email-liang.z.li@intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Diffstat (limited to 'migration')
-rw-r--r-- | migration/ram.c | 50 |
1 files changed, 25 insertions, 25 deletions
diff --git a/migration/ram.c b/migration/ram.c index 59473d9..a44b4f0 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -264,7 +264,6 @@ struct CompressParam { typedef struct CompressParam CompressParam; struct DecompressParam { - bool start; bool done; bool quit; QemuMutex mutex; @@ -830,15 +829,6 @@ static int do_compress_ram_page(QEMUFile *f, RAMBlock *block, return bytes_sent; } -static inline void start_decompression(DecompressParam *param) -{ - param->done = false; - qemu_mutex_lock(¶m->mutex); - param->start = true; - qemu_cond_signal(¶m->cond); - qemu_mutex_unlock(¶m->mutex); -} - static uint64_t bytes_transferred; static void flush_compressed_data(QEMUFile *f) @@ -2198,30 +2188,37 @@ static void *do_data_decompress(void *opaque) { DecompressParam *param = opaque; unsigned long pagesize; + uint8_t *des; + int len; + qemu_mutex_lock(¶m->mutex); while (!param->quit) { - qemu_mutex_lock(¶m->mutex); - while (!param->start && !param->quit) { - qemu_cond_wait(¶m->cond, ¶m->mutex); - } - if (!param->quit) { + if (param->des) { + des = param->des; + len = param->len; + param->des = 0; + qemu_mutex_unlock(¶m->mutex); + pagesize = TARGET_PAGE_SIZE; /* uncompress() will return failed in some case, especially * when the page is dirted when doing the compression, it's * not a problem because the dirty page will be retransferred * and uncompress() won't break the data in other pages. */ - uncompress((Bytef *)param->des, &pagesize, - (const Bytef *)param->compbuf, param->len); - } - param->start = false; - qemu_mutex_unlock(¶m->mutex); + uncompress((Bytef *)des, &pagesize, + (const Bytef *)param->compbuf, len); - qemu_mutex_lock(&decomp_done_lock); - param->done = true; - qemu_cond_signal(&decomp_done_cond); - qemu_mutex_unlock(&decomp_done_lock); + qemu_mutex_lock(&decomp_done_lock); + param->done = true; + qemu_cond_signal(&decomp_done_cond); + qemu_mutex_unlock(&decomp_done_lock); + + qemu_mutex_lock(¶m->mutex); + } else { + qemu_cond_wait(¶m->cond, ¶m->mutex); + } } + qemu_mutex_unlock(¶m->mutex); return NULL; } @@ -2298,10 +2295,13 @@ static void decompress_data_with_multi_threads(QEMUFile *f, while (true) { for (idx = 0; idx < thread_count; idx++) { if (decomp_param[idx].done) { + decomp_param[idx].done = false; + qemu_mutex_lock(&decomp_param[idx].mutex); qemu_get_buffer(f, decomp_param[idx].compbuf, len); decomp_param[idx].des = host; decomp_param[idx].len = len; - start_decompression(&decomp_param[idx]); + qemu_cond_signal(&decomp_param[idx].cond); + qemu_mutex_unlock(&decomp_param[idx].mutex); break; } } |