From b8fb8cb748497aa070304eec27b03edd3b05373d Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Wed, 23 Sep 2015 15:27:10 +0100 Subject: [PATCH] Move dirty page search state into separate structure Pull the search state for one iteration of the dirty page search into a structure. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Amit Shah Message-Id: <1443018431-11170-2-git-send-email-dgilbert@redhat.com> Reviewed-by: Amit Shah Signed-off-by: Amit Shah --- migration/ram.c | 55 +++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 20 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 7df9157ec7..d79d79de1f 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -227,6 +227,17 @@ static uint64_t migration_dirty_pages; static uint32_t last_version; static bool ram_bulk_stage; +/* used by the search for pages to send */ +struct PageSearchStatus { + /* Current block being searched */ + RAMBlock *block; + /* Current offset to search from */ + ram_addr_t offset; + /* Set once we wrap around */ + bool complete_round; +}; +typedef struct PageSearchStatus PageSearchStatus; + struct CompressParam { bool start; bool done; @@ -531,7 +542,6 @@ static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length) cpu_physical_memory_sync_dirty_bitmap(bitmap, start, length); } - /* Fix me: there are too many global variables used in migration process. */ static int64_t start_time; static int64_t bytes_xfer_prev; @@ -923,26 +933,30 @@ static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block, static int ram_find_and_save_block(QEMUFile *f, bool last_stage, uint64_t *bytes_transferred) { - RAMBlock *block = last_seen_block; - ram_addr_t offset = last_offset; - bool complete_round = false; + PageSearchStatus pss; int pages = 0; - if (!block) - block = QLIST_FIRST_RCU(&ram_list.blocks); + pss.block = last_seen_block; + pss.offset = last_offset; + pss.complete_round = false; + + if (!pss.block) { + pss.block = QLIST_FIRST_RCU(&ram_list.blocks); + } while (true) { - offset = migration_bitmap_find_and_reset_dirty(block, offset); - if (complete_round && block == last_seen_block && - offset >= last_offset) { + pss.offset = migration_bitmap_find_and_reset_dirty(pss.block, + pss.offset); + if (pss.complete_round && pss.block == last_seen_block && + pss.offset >= last_offset) { break; } - if (offset >= block->used_length) { - offset = 0; - block = QLIST_NEXT_RCU(block, next); - if (!block) { - block = QLIST_FIRST_RCU(&ram_list.blocks); - complete_round = true; + if (pss.offset >= pss.block->used_length) { + pss.offset = 0; + pss.block = QLIST_NEXT_RCU(pss.block, next); + if (!pss.block) { + pss.block = QLIST_FIRST_RCU(&ram_list.blocks); + pss.complete_round = true; ram_bulk_stage = false; if (migrate_use_xbzrle()) { /* If xbzrle is on, stop using the data compression at this @@ -954,23 +968,24 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage, } } else { if (compression_switch && migrate_use_compression()) { - pages = ram_save_compressed_page(f, block, offset, last_stage, + pages = ram_save_compressed_page(f, pss.block, pss.offset, + last_stage, bytes_transferred); } else { - pages = ram_save_page(f, block, offset, last_stage, + pages = ram_save_page(f, pss.block, pss.offset, last_stage, bytes_transferred); } /* if page is unmodified, continue to the next */ if (pages > 0) { - last_sent_block = block; + last_sent_block = pss.block; break; } } } - last_seen_block = block; - last_offset = offset; + last_seen_block = pss.block; + last_offset = pss.offset; return pages; } -- 2.11.0