From 6d52c264fa9a7a78ee532f45d24704491ce4c431 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Wed, 1 Aug 2018 13:55:09 +0100 Subject: [PATCH 05/21] migration: introduce control_save_page() RH-Author: Dr. David Alan Gilbert Message-id: <20180801135522.11658-6-dgilbert@redhat.com> Patchwork-id: 81581 O-Subject: [qemu-kvm RHEL8/virt212 PATCH 05/18] migration: introduce control_save_page() Bugzilla: 1594384 RH-Acked-by: Peter Xu RH-Acked-by: John Snow RH-Acked-by: Juan Quintela From: Xiao Guangrong Abstract the common function control_save_page() to cleanup the code, no logic is changed Reviewed-by: Peter Xu Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Xiao Guangrong Message-Id: <20180330075128.26919-6-xiaoguangrong@tencent.com> Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit 059ff0fb29dd3a56ac2843676915efc279938c6b) Signed-off-by: Danilo C. L. de Paula --- migration/ram.c | 174 +++++++++++++++++++++++++++++--------------------------- 1 file changed, 89 insertions(+), 85 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index cd6d98a..8dc98a5 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -975,6 +975,44 @@ static void ram_release_pages(const char *rbname, uint64_t offset, int pages) ram_discard_range(rbname, offset, pages << TARGET_PAGE_BITS); } +/* + * @pages: the number of pages written by the control path, + * < 0 - error + * > 0 - number of pages written + * + * Return true if the pages has been saved, otherwise false is returned. + */ +static bool control_save_page(RAMState *rs, RAMBlock *block, ram_addr_t offset, + int *pages) +{ + uint64_t bytes_xmit = 0; + int ret; + + *pages = -1; + ret = ram_control_save_page(rs->f, block->offset, offset, TARGET_PAGE_SIZE, + &bytes_xmit); + if (ret == RAM_SAVE_CONTROL_NOT_SUPP) { + return false; + } + + if (bytes_xmit) { + ram_counters.transferred += bytes_xmit; + *pages = 1; + } + + if (ret == RAM_SAVE_CONTROL_DELAYED) { + return true; + } + + if (bytes_xmit > 0) { + ram_counters.normal++; + } else if (bytes_xmit == 0) { + ram_counters.duplicate++; + } + + return true; +} + /** * ram_save_page: send the given page to the stream * @@ -991,56 +1029,36 @@ static void ram_release_pages(const char *rbname, uint64_t offset, int pages) static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage) { int pages = -1; - uint64_t bytes_xmit; - ram_addr_t current_addr; uint8_t *p; - int ret; bool send_async = true; RAMBlock *block = pss->block; ram_addr_t offset = pss->page << TARGET_PAGE_BITS; + ram_addr_t current_addr = block->offset + offset; p = block->host + offset; trace_ram_save_page(block->idstr, (uint64_t)offset, p); - /* In doubt sent page as normal */ - bytes_xmit = 0; - ret = ram_control_save_page(rs->f, block->offset, - offset, TARGET_PAGE_SIZE, &bytes_xmit); - if (bytes_xmit) { - ram_counters.transferred += bytes_xmit; - pages = 1; + if (control_save_page(rs, block, offset, &pages)) { + return pages; } XBZRLE_cache_lock(); - - current_addr = block->offset + offset; - - if (ret != RAM_SAVE_CONTROL_NOT_SUPP) { - if (ret != RAM_SAVE_CONTROL_DELAYED) { - if (bytes_xmit > 0) { - ram_counters.normal++; - } else if (bytes_xmit == 0) { - ram_counters.duplicate++; - } - } - } else { - pages = save_zero_page(rs, block, offset); - if (pages > 0) { - /* Must let xbzrle know, otherwise a previous (now 0'd) cached - * page would be stale + pages = save_zero_page(rs, block, offset); + if (pages > 0) { + /* Must let xbzrle know, otherwise a previous (now 0'd) cached + * page would be stale + */ + xbzrle_cache_zero_page(rs, current_addr); + ram_release_pages(block->idstr, offset, pages); + } else if (!rs->ram_bulk_stage && + !migration_in_postcopy() && migrate_use_xbzrle()) { + pages = save_xbzrle_page(rs, &p, current_addr, block, + offset, last_stage); + if (!last_stage) { + /* Can't send this cached data async, since the cache page + * might get updated before it gets to the wire */ - xbzrle_cache_zero_page(rs, current_addr); - ram_release_pages(block->idstr, offset, pages); - } else if (!rs->ram_bulk_stage && - !migration_in_postcopy() && migrate_use_xbzrle()) { - pages = save_xbzrle_page(rs, &p, current_addr, block, - offset, last_stage); - if (!last_stage) { - /* Can't send this cached data async, since the cache page - * might get updated before it gets to the wire - */ - send_async = false; - } + send_async = false; } } @@ -1175,63 +1193,49 @@ static int ram_save_compressed_page(RAMState *rs, PageSearchStatus *pss, bool last_stage) { int pages = -1; - uint64_t bytes_xmit = 0; uint8_t *p; - int ret; RAMBlock *block = pss->block; ram_addr_t offset = pss->page << TARGET_PAGE_BITS; p = block->host + offset; - ret = ram_control_save_page(rs->f, block->offset, - offset, TARGET_PAGE_SIZE, &bytes_xmit); - if (bytes_xmit) { - ram_counters.transferred += bytes_xmit; - pages = 1; + if (control_save_page(rs, block, offset, &pages)) { + return pages; } - if (ret != RAM_SAVE_CONTROL_NOT_SUPP) { - if (ret != RAM_SAVE_CONTROL_DELAYED) { - if (bytes_xmit > 0) { - ram_counters.normal++; - } else if (bytes_xmit == 0) { - ram_counters.duplicate++; - } + + /* 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 != rs->last_sent_block) { + flush_compressed_data(rs); + pages = save_zero_page(rs, block, offset); + if (pages > 0) { + ram_release_pages(block->idstr, offset, pages); + } else { + /* + * Make sure the first page is sent out before other pages. + * + * we post it as normal page as compression will take much + * CPU resource. + */ + ram_counters.transferred += save_page_header(rs, rs->f, block, + offset | RAM_SAVE_FLAG_PAGE); + qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE, + migrate_release_ram() & + migration_in_postcopy()); + ram_counters.transferred += TARGET_PAGE_SIZE; + ram_counters.normal++; + pages = 1; } } 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 != rs->last_sent_block) { - flush_compressed_data(rs); - pages = save_zero_page(rs, block, offset); - if (pages > 0) { - ram_release_pages(block->idstr, offset, pages); - } else { - /* - * Make sure the first page is sent out before other pages. - * - * we post it as normal page as compression will take much - * CPU resource. - */ - ram_counters.transferred += save_page_header(rs, rs->f, block, - offset | RAM_SAVE_FLAG_PAGE); - qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE, - migrate_release_ram() & - migration_in_postcopy()); - ram_counters.transferred += TARGET_PAGE_SIZE; - ram_counters.normal++; - pages = 1; - } + pages = save_zero_page(rs, block, offset); + if (pages == -1) { + pages = compress_page_with_multi_thread(rs, block, offset); } else { - pages = save_zero_page(rs, block, offset); - if (pages == -1) { - pages = compress_page_with_multi_thread(rs, block, offset); - } else { - ram_release_pages(block->idstr, offset, pages); - } + ram_release_pages(block->idstr, offset, pages); } } -- 1.8.3.1