From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YbRna-0000MV-Mo for qemu-devel@nongnu.org; Fri, 27 Mar 2015 06:47:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YbRnX-0003xK-G9 for qemu-devel@nongnu.org; Fri, 27 Mar 2015 06:47:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46973) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YbRnX-0003x8-9A for qemu-devel@nongnu.org; Fri, 27 Mar 2015 06:47:31 -0400 From: Juan Quintela In-Reply-To: <1427099549-10633-9-git-send-email-liang.z.li@intel.com> (Liang Li's message of "Mon, 23 Mar 2015 16:32:23 +0800") References: <1427099549-10633-1-git-send-email-liang.z.li@intel.com> <1427099549-10633-9-git-send-email-liang.z.li@intel.com> Date: Fri, 27 Mar 2015 11:47:25 +0100 Message-ID: <87oanevhs2.fsf@neno.neno> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [v6 08/14] migration: Add the core code of multi-thread compression Reply-To: quintela@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Liang Li Cc: qemu-devel@nongnu.org, lcapitulino@redhat.com, yang.z.zhang@intel.com, amit.shah@redhat.com, dgilbert@redhat.com Liang Li wrote: > Implement the core logic of the multiple thread compression. At this > point, multiple thread compression can't co-work with xbzrle yet. > > Signed-off-by: Liang Li > Signed-off-by: Yang Zhang Coming back to here, as we have the full code. > --- > arch_init.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 177 insertions(+), 7 deletions(-) > > diff --git a/arch_init.c b/arch_init.c > index 48cae22..9f63c0f 100644 > --- a/arch_init.c > +++ b/arch_init.c > @@ -355,12 +355,33 @@ static DecompressParam *decomp_param; > static QemuThread *decompress_threads; > static uint8_t *compressed_data_buf; > > +static int do_compress_ram_page(CompressParam *param); > + > static void *do_data_compress(void *opaque) > { > - while (!quit_comp_thread) { > + CompressParam *param = opaque; > > - /* To be done */ Change this line to > + while (!quit_comp_thread) { while(true) { > + qemu_mutex_lock(¶m->mutex); > + /* Re-check the quit_comp_thread in case of > + * terminate_compression_threads is called just before > + * qemu_mutex_lock(¶m->mutex) and after > + * while(!quit_comp_thread), re-check it here can make > + * sure the compression thread terminate as expected. > + */ Change this > + while (!param->start && !quit_comp_thread) { to while (!param->start && !parm->quit) { > + qemu_cond_wait(¶m->cond, ¶m->mutex); > + } And this > + if (!quit_comp_thread) { to if (!param->quit) { > + do_compress_ram_page(param); > + } Take care here of exiting correctly of the loop. Notice that the only case where we are not going to take the look is the last iteration, so I think the optimization don't gives us nothing (in this place), no? > + param->start = false; > + qemu_mutex_unlock(¶m->mutex); > > + qemu_mutex_lock(comp_done_lock); > + param->done = true; > + qemu_cond_signal(comp_done_cond); > + qemu_mutex_unlock(comp_done_lock); > } > > return NULL; > @@ -368,9 +389,15 @@ static void *do_data_compress(void *opaque) > > static inline void terminate_compression_threads(void) > { > - quit_comp_thread = true; > + int idx, thread_count; > > - /* To be done */ > + thread_count = migrate_compress_threads(); > + quit_comp_thread = true; > + for (idx = 0; idx < thread_count; idx++) { > + qemu_mutex_lock(&comp_param[idx].mutex); Add this comp_param[idx].quit = true; And for now on, quit_comp_thread is only used on migration_thread, so it should be safe to use, no? flush_compresed_data() is only ever called from the migration_thread, so no lock there needed either. > + qemu_cond_signal(&comp_param[idx].cond); > + qemu_mutex_unlock(&comp_param[idx].mutex); > + } > } > > void migrate_compress_threads_join(void) > @@ -420,6 +447,7 @@ void migrate_compress_threads_create(void) > * it's ops to empty. > */ > comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops); > + comp_param[i].done = true; > qemu_mutex_init(&comp_param[i].mutex); > qemu_cond_init(&comp_param[i].cond); > qemu_thread_create(compress_threads + i, "compress", > @@ -829,6 +857,97 @@ static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset, > return pages; > } > > +static int do_compress_ram_page(CompressParam *param) > +{ > + int bytes_sent, blen; > + uint8_t *p; > + RAMBlock *block = param->block; > + ram_addr_t offset = param->offset; > + > + p = memory_region_get_ram_ptr(block->mr) + (offset & TARGET_PAGE_MASK); > + > + bytes_sent = save_page_header(param->file, block, offset | > + RAM_SAVE_FLAG_COMPRESS_PAGE); > + blen = qemu_put_compression_data(param->file, p, TARGET_PAGE_SIZE, > + migrate_compress_level()); > + bytes_sent += blen; > + atomic_inc(&acct_info.norm_pages); > + > + return bytes_sent; > +} > + > +static inline void start_compression(CompressParam *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) > +{ > + int idx, len, thread_count; > + > + if (!migrate_use_compression()) { > + return; > + } > + thread_count = migrate_compress_threads(); > + for (idx = 0; idx < thread_count; idx++) { > + if (!comp_param[idx].done) { > + qemu_mutex_lock(comp_done_lock); > + while (!comp_param[idx].done && !quit_comp_thread) { > + qemu_cond_wait(comp_done_cond, comp_done_lock); > + } > + qemu_mutex_unlock(comp_done_lock); > + } > + if (!quit_comp_thread) { > + len = qemu_put_qemu_file(f, comp_param[idx].file); > + bytes_transferred += len; > + } > + } > +} > + > +static inline void set_compress_params(CompressParam *param, RAMBlock *block, > + ram_addr_t offset) > +{ > + param->block = block; > + param->offset = offset; > +} > + > +static int compress_page_with_multi_thread(QEMUFile *f, RAMBlock *block, > + ram_addr_t offset, > + uint64_t *bytes_transferred) > +{ > + int idx, thread_count, bytes_xmit = -1, pages = -1; > + > + thread_count = migrate_compress_threads(); > + qemu_mutex_lock(comp_done_lock); > + while (true) { > + for (idx = 0; idx < thread_count; idx++) { > + if (comp_param[idx].done) { > + bytes_xmit = qemu_put_qemu_file(f, comp_param[idx].file); > + set_compress_params(&comp_param[idx], block, offset); > + start_compression(&comp_param[idx]); > + pages = 1; > + *bytes_transferred += bytes_xmit; > + break; > + } > + } > + if (pages > 0) { > + break; > + } else { > + qemu_cond_wait(comp_done_cond, comp_done_lock); > + } > + } > + qemu_mutex_unlock(comp_done_lock); > + > + return pages; > +} > + > /** > * ram_save_compressed_page: compress the given page and send it to the stream > * > @@ -845,8 +964,59 @@ static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block, > uint64_t *bytes_transferred) > { > int pages = -1; > + uint64_t bytes_xmit; > + MemoryRegion *mr = block->mr; > + uint8_t *p; > + int ret; > + > + p = memory_region_get_ram_ptr(mr) + offset; > > - /* To be done*/ > + bytes_xmit = 0; > + ret = ram_control_save_page(f, block->offset, > + offset, TARGET_PAGE_SIZE, &bytes_xmit); > + if (bytes_xmit) { > + *bytes_transferred += bytes_xmit; > + pages = 1; > + } > + if (block == last_sent_block) { > + offset |= RAM_SAVE_FLAG_CONTINUE; > + } > + if (ret != RAM_SAVE_CONTROL_NOT_SUPP) { > + if (ret != RAM_SAVE_CONTROL_DELAYED) { > + if (bytes_xmit > 0) { > + acct_info.norm_pages++; > + } else if (bytes_xmit == 0) { > + acct_info.dup_pages++; > + } > + } > + } else { > + /* When starting the process of a new block, the first page of > + * the block should be sent out before other pages in the same > + * block, and all the pages in last block should have been sent > + * out, keeping this order is important, because the 'cont' flag > + * is used to avoid resending the block name. > + */ > + if (block != last_sent_block) { > + flush_compressed_data(f); > + pages = save_zero_page(f, block, offset, p, bytes_transferred); > + if (pages == -1) { > + set_compress_params(&comp_param[0], block, offset); > + /* Use the qemu thread to compress the data to make sure the > + * first page is sent out before other pages > + */ > + bytes_xmit = do_compress_ram_page(&comp_param[0]); > + qemu_put_qemu_file(f, comp_param[0].file); > + *bytes_transferred += bytes_xmit; > + pages = 1; > + } > + } else { > + pages = save_zero_page(f, block, offset, p, bytes_transferred); > + if (pages == -1) { > + pages = compress_page_with_multi_thread(f, block, offset, > + bytes_transferred); > + } > + } > + } > > return pages; > } > @@ -914,8 +1084,6 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage, > return pages; > } > > -static uint64_t bytes_transferred; > - > void acct_update_position(QEMUFile *f, size_t size, bool zero) > { > uint64_t pages = size / TARGET_PAGE_SIZE; > @@ -1129,6 +1297,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) > } > i++; > } > + flush_compressed_data(f); > rcu_read_unlock(); > > /* > @@ -1170,6 +1339,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque) > } > } > > + flush_compressed_data(f); > ram_control_after_iterate(f, RAM_CONTROL_FINISH); > migration_end();