From patchwork Mon Aug 19 06:18:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Yang X-Patchwork-Id: 1149045 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46BkLS2Lcyz9sMr for ; Mon, 19 Aug 2019 16:20:16 +1000 (AEST) Received: from localhost ([::1]:45240 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzb1a-0002Hi-A0 for incoming@patchwork.ozlabs.org; Mon, 19 Aug 2019 02:20:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51774) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzb11-0002E0-7i for qemu-devel@nongnu.org; Mon, 19 Aug 2019 02:19:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hzb0z-0003EP-DR for qemu-devel@nongnu.org; Mon, 19 Aug 2019 02:19:39 -0400 Received: from mga11.intel.com ([192.55.52.93]:9382) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hzb0z-0003CJ-4B for qemu-devel@nongnu.org; Mon, 19 Aug 2019 02:19:37 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Aug 2019 23:19:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,403,1559545200"; d="scan'208";a="180265819" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga003.jf.intel.com with ESMTP; 18 Aug 2019 23:19:35 -0700 From: Wei Yang To: qemu-devel@nongnu.org Date: Mon, 19 Aug 2019 14:18:42 +0800 Message-Id: <20190819061843.28642-3-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190819061843.28642-1-richardw.yang@linux.intel.com> References: <20190819061843.28642-1-richardw.yang@linux.intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 Subject: [Qemu-devel] [PATCH 2/3] migration/postcopy: unsentmap is not necessary for postcopy X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pbonzini@redhat.com, Wei Yang , dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Commit f3f491fcd6dd594ba695 ('Postcopy: Maintain unsentmap') introduced unsentmap to track not yet sent pages. This is not necessary since: * unsentmap is a sub-set of bmap before postcopy start * unsentmap is the summation of bmap and unsentmap after canonicalizing This patch just removes it. Signed-off-by: Wei Yang Reviewed-by: Dr. David Alan Gilbert --- include/exec/ram_addr.h | 6 ---- migration/ram.c | 80 ++++++++--------------------------------- 2 files changed, 14 insertions(+), 72 deletions(-) diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index a327a80cfe..e96e621de5 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -44,12 +44,6 @@ struct RAMBlock { size_t page_size; /* dirty bitmap used during migration */ unsigned long *bmap; - /* bitmap of pages that haven't been sent even once - * only maintained and used in postcopy at the moment - * where it's used to send the dirtymap at the start - * of the postcopy phase - */ - unsigned long *unsentmap; /* bitmap of already received pages in postcopy */ unsigned long *receivedmap; diff --git a/migration/ram.c b/migration/ram.c index 075ddc468c..066eb4755f 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2348,7 +2348,7 @@ static bool get_queued_page(RAMState *rs, PageSearchStatus *pss) dirty = test_bit(page, block->bmap); if (!dirty) { trace_get_queued_page_not_dirty(block->idstr, (uint64_t)offset, - page, test_bit(page, block->unsentmap)); + page, test_bit(page, block->bmap)); } else { trace_get_queued_page(block->idstr, (uint64_t)offset, page); } @@ -2619,10 +2619,6 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss, } pages += tmppages; - if (pss->block->unsentmap) { - clear_bit(pss->page, pss->block->unsentmap); - } - pss->page++; } while ((pss->page & (pagesize_bits - 1)) && offset_in_ramblock(pss->block, pss->page << TARGET_PAGE_BITS)); @@ -2776,8 +2772,6 @@ static void ram_save_cleanup(void *opaque) block->clear_bmap = NULL; g_free(block->bmap); block->bmap = NULL; - g_free(block->unsentmap); - block->unsentmap = NULL; } xbzrle_cleanup(); @@ -2857,8 +2851,6 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms) * Returns zero on success * * Callback from postcopy_each_ram_send_discard for each RAMBlock - * Note: At this point the 'unsentmap' is the processed bitmap combined - * with the dirtymap; so a '1' means it's either dirty or unsent. * * @ms: current migration state * @block: RAMBlock to discard @@ -2867,17 +2859,17 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block) { unsigned long end = block->used_length >> TARGET_PAGE_BITS; unsigned long current; - unsigned long *unsentmap = block->unsentmap; + unsigned long *bitmap = block->bmap; for (current = 0; current < end; ) { - unsigned long one = find_next_bit(unsentmap, end, current); + unsigned long one = find_next_bit(bitmap, end, current); unsigned long zero, discard_length; if (one >= end) { break; } - zero = find_next_zero_bit(unsentmap, end, one + 1); + zero = find_next_zero_bit(bitmap, end, one + 1); if (zero >= end) { discard_length = end - one; @@ -2938,16 +2930,12 @@ static int postcopy_each_ram_send_discard(MigrationState *ms) * clean, not a mix. This function canonicalizes the bitmaps. * * @ms: current migration state - * @unsent_pass: if true we need to canonicalize partially unsent host pages - * otherwise we need to canonicalize partially dirty host pages * @block: block that contains the page we want to canonicalize */ -static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, - RAMBlock *block) +static void postcopy_chunk_hostpages_pass(MigrationState *ms, RAMBlock *block) { RAMState *rs = ram_state; unsigned long *bitmap = block->bmap; - unsigned long *unsentmap = block->unsentmap; unsigned int host_ratio = block->page_size / TARGET_PAGE_SIZE; unsigned long pages = block->used_length >> TARGET_PAGE_BITS; unsigned long run_start; @@ -2957,13 +2945,8 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, return; } - if (unsent_pass) { - /* Find a sent page */ - run_start = find_next_zero_bit(unsentmap, pages, 0); - } else { - /* Find a dirty page */ - run_start = find_next_bit(bitmap, pages, 0); - } + /* Find a dirty page */ + run_start = find_next_bit(bitmap, pages, 0); while (run_start < pages) { @@ -2973,11 +2956,7 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, */ if (QEMU_IS_ALIGNED(run_start, host_ratio)) { /* Find the end of this run */ - if (unsent_pass) { - run_start = find_next_bit(unsentmap, pages, run_start + 1); - } else { - run_start = find_next_zero_bit(bitmap, pages, run_start + 1); - } + run_start = find_next_zero_bit(bitmap, pages, run_start + 1); /* * If the end isn't at the start of a host page, then the * run doesn't finish at the end of a host page @@ -2994,9 +2973,6 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, /* Clean up the bitmap */ for (page = fixup_start_addr; page < fixup_start_addr + host_ratio; page++) { - /* All pages in this host page are now not sent */ - set_bit(page, unsentmap); - /* * Remark them as dirty, updating the count for any pages * that weren't previously dirty. @@ -3005,13 +2981,8 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, } } - if (unsent_pass) { - /* Find the next sent page for the next iteration */ - run_start = find_next_zero_bit(unsentmap, pages, run_start); - } else { - /* Find the next dirty page for the next iteration */ - run_start = find_next_bit(bitmap, pages, run_start); - } + /* Find the next dirty page for the next iteration */ + run_start = find_next_bit(bitmap, pages, run_start); } } @@ -3033,13 +3004,10 @@ static int postcopy_chunk_hostpages(MigrationState *ms, RAMBlock *block) { postcopy_discard_send_init(ms, block->idstr); - /* First pass: Discard all partially sent host pages */ - postcopy_chunk_hostpages_pass(ms, true, block); /* - * Second pass: Ensure that all partially dirty host pages are made - * fully dirty. + * Ensure that all partially dirty host pages are made fully dirty. */ - postcopy_chunk_hostpages_pass(ms, false, block); + postcopy_chunk_hostpages_pass(ms, block); postcopy_discard_send_finish(ms); return 0; @@ -3077,19 +3045,6 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms) rs->last_page = 0; RAMBLOCK_FOREACH_NOT_IGNORED(block) { - unsigned long pages = block->used_length >> TARGET_PAGE_BITS; - unsigned long *bitmap = block->bmap; - unsigned long *unsentmap = block->unsentmap; - - if (!unsentmap) { - /* We don't have a safe way to resize the sentmap, so - * if the bitmap was resized it will be NULL at this - * point. - */ - error_report("migration ram resized during precopy phase"); - rcu_read_unlock(); - return -EINVAL; - } /* Deal with TPS != HPS and huge pages */ ret = postcopy_chunk_hostpages(ms, block); if (ret) { @@ -3097,12 +3052,9 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms) return ret; } - /* - * Update the unsentmap to be unsentmap = unsentmap | dirty - */ - bitmap_or(unsentmap, unsentmap, bitmap, pages); #ifdef DEBUG_POSTCOPY - ram_debug_dump_bitmap(unsentmap, true, pages); + ram_debug_dump_bitmap(block->bmap, true, + block->used_length >> TARGET_PAGE_BITS); #endif } trace_ram_postcopy_send_discard_bitmap(); @@ -3270,10 +3222,6 @@ static void ram_list_init_bitmaps(void) bitmap_set(block->bmap, 0, pages); block->clear_bmap_shift = shift; block->clear_bmap = bitmap_new(clear_bmap_size(pages, shift)); - if (migrate_postcopy_ram()) { - block->unsentmap = bitmap_new(pages); - bitmap_set(block->unsentmap, 0, pages); - } } } }