From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56646) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f176K-0000rF-LJ for qemu-devel@nongnu.org; Wed, 28 Mar 2018 05:10:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f176H-0004yP-Vj for qemu-devel@nongnu.org; Wed, 28 Mar 2018 05:10:36 -0400 Received: from mail-pf0-x243.google.com ([2607:f8b0:400e:c00::243]:45875) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1f176H-0004yA-Md for qemu-devel@nongnu.org; Wed, 28 Mar 2018 05:10:33 -0400 Received: by mail-pf0-x243.google.com with SMTP id l27so730936pfk.12 for ; Wed, 28 Mar 2018 02:10:33 -0700 (PDT) From: guangrong.xiao@gmail.com Date: Tue, 27 Mar 2018 17:10:36 +0800 Message-Id: <20180327091043.30220-4-xiaoguangrong@tencent.com> In-Reply-To: <20180327091043.30220-1-xiaoguangrong@tencent.com> References: <20180327091043.30220-1-xiaoguangrong@tencent.com> Subject: [Qemu-devel] [PATCH v2 03/10] migration: stop decompression to allocate and free memory frequently List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: pbonzini@redhat.com, mst@redhat.com, mtosatti@redhat.com Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, dgilbert@redhat.com, peterx@redhat.com, jiang.biao2@zte.com.cn, wei.w.wang@intel.com, Xiao Guangrong From: Xiao Guangrong Current code uses uncompress() to decompress 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 So, we maintain the memory by ourselves and reuse it for each decompression Reviewed-by: Jiang Biao Signed-off-by: Xiao Guangrong --- migration/ram.c | 110 ++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 80 insertions(+), 30 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index e043a192e1..6b699650ca 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -281,6 +281,7 @@ struct DecompressParam { void *des; uint8_t *compbuf; int len; + z_stream stream; }; typedef struct DecompressParam DecompressParam; @@ -2526,6 +2527,31 @@ void ram_handle_compressed(void *host, uint8_t ch, uint64_t size) } } +/* return the size after decompression, or negative value on error */ +static int +qemu_uncompress_data(z_stream *stream, uint8_t *dest, size_t dest_len, + const uint8_t *source, size_t source_len) +{ + int err; + + err = inflateReset(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 = inflate(stream, Z_NO_FLUSH); + if (err != Z_STREAM_END) { + return -1; + } + + return stream->total_out; +} + static void *do_data_decompress(void *opaque) { DecompressParam *param = opaque; @@ -2542,13 +2568,13 @@ static void *do_data_decompress(void *opaque) 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 + /* qemu_uncompress_data() will return failed in some case, + * especially when the page is dirtied 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 *)des, &pagesize, - (const Bytef *)param->compbuf, len); + qemu_uncompress_data(¶m->stream, des, pagesize, param->compbuf, + len); qemu_mutex_lock(&decomp_done_lock); param->done = true; @@ -2583,30 +2609,6 @@ static void wait_for_decompress_done(void) qemu_mutex_unlock(&decomp_done_lock); } -static void compress_threads_load_setup(void) -{ - int i, thread_count; - - if (!migrate_use_compression()) { - return; - } - thread_count = migrate_decompress_threads(); - decompress_threads = g_new0(QemuThread, thread_count); - decomp_param = g_new0(DecompressParam, thread_count); - qemu_mutex_init(&decomp_done_lock); - qemu_cond_init(&decomp_done_cond); - for (i = 0; i < thread_count; i++) { - qemu_mutex_init(&decomp_param[i].mutex); - qemu_cond_init(&decomp_param[i].cond); - decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE)); - decomp_param[i].done = true; - decomp_param[i].quit = false; - qemu_thread_create(decompress_threads + i, "decompress", - do_data_decompress, decomp_param + i, - QEMU_THREAD_JOINABLE); - } -} - static void compress_threads_load_cleanup(void) { int i, thread_count; @@ -2616,16 +2618,27 @@ static void compress_threads_load_cleanup(void) } thread_count = migrate_decompress_threads(); for (i = 0; i < thread_count; i++) { + /* see the comments in compress_threads_save_cleanup() */ + if (!decomp_param[i].stream.opaque) { + break; + } + qemu_mutex_lock(&decomp_param[i].mutex); decomp_param[i].quit = true; qemu_cond_signal(&decomp_param[i].cond); qemu_mutex_unlock(&decomp_param[i].mutex); } for (i = 0; i < thread_count; i++) { + if (!decomp_param[i].stream.opaque) { + break; + } + qemu_thread_join(decompress_threads + i); qemu_mutex_destroy(&decomp_param[i].mutex); qemu_cond_destroy(&decomp_param[i].cond); g_free(decomp_param[i].compbuf); + inflateEnd(&decomp_param[i].stream); + decomp_param[i].stream.opaque = NULL; } g_free(decompress_threads); g_free(decomp_param); @@ -2633,6 +2646,40 @@ static void compress_threads_load_cleanup(void) decomp_param = NULL; } +static int compress_threads_load_setup(void) +{ + int i, thread_count; + + if (!migrate_use_compression()) { + return 0; + } + + thread_count = migrate_decompress_threads(); + decompress_threads = g_new0(QemuThread, thread_count); + decomp_param = g_new0(DecompressParam, thread_count); + qemu_mutex_init(&decomp_done_lock); + qemu_cond_init(&decomp_done_cond); + for (i = 0; i < thread_count; i++) { + if (inflateInit(&decomp_param[i].stream) != Z_OK) { + goto exit; + } + decomp_param[i].stream.opaque = &decomp_param[i]; + + qemu_mutex_init(&decomp_param[i].mutex); + qemu_cond_init(&decomp_param[i].cond); + decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE)); + decomp_param[i].done = true; + decomp_param[i].quit = false; + qemu_thread_create(decompress_threads + i, "decompress", + do_data_decompress, decomp_param + i, + QEMU_THREAD_JOINABLE); + } + return 0; +exit: + compress_threads_load_cleanup(); + return -1; +} + static void decompress_data_with_multi_threads(QEMUFile *f, void *host, int len) { @@ -2672,8 +2719,11 @@ static void decompress_data_with_multi_threads(QEMUFile *f, */ static int ram_load_setup(QEMUFile *f, void *opaque) { + if (compress_threads_load_setup()) { + return -1; + } + xbzrle_load_setup(); - compress_threads_load_setup(); ramblock_recv_map_init(); return 0; } -- 2.14.3