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Wed, 8 Feb 2023 13:30:23 +0000 (UTC) Received: from secure.mitica (unknown [10.39.192.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id CFC01C15BAD; Wed, 8 Feb 2023 13:30:21 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: "Dr. David Alan Gilbert" , Markus Armbruster , Juan Quintela , Marcel Apfelbaum , Yanan Wang , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Eduardo Habkost , Eric Blake Subject: [PATCH v3 4/6] migration: Make find_dirty_block() return a single parameter Date: Wed, 8 Feb 2023 14:30:08 +0100 Message-Id: <20230208133010.17323-5-quintela@redhat.com> In-Reply-To: <20230208133010.17323-1-quintela@redhat.com> References: <20230208133010.17323-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org We used to return two bools, just return a single int with the following meaning: old return / again / new return false false PAGE_ALL_CLEAN false true PAGE_TRY_AGAIN true true PAGE_DIRTY_FOUND /* We don't care about again at all */ Signed-off-by: Juan Quintela --- migration/ram.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 5c406f2c1d..e05503f825 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1546,17 +1546,23 @@ retry: return pages; } +#define PAGE_ALL_CLEAN 0 +#define PAGE_TRY_AGAIN 1 +#define PAGE_DIRTY_FOUND 2 /** * find_dirty_block: find the next dirty page and update any state * associated with the search process. * - * Returns true if a page is found + * Returns: + * PAGE_ALL_CLEAN: no dirty page found, give up + * PAGE_TRY_AGAIN: no dirty page found, retry for next block + * PAGE_DIRTY_FOUND: dirty page found * * @rs: current RAM state * @pss: data about the state of the current dirty page scan * @again: set to false if the search has scanned the whole of RAM */ -static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again) +static int find_dirty_block(RAMState *rs, PageSearchStatus *pss) { /* Update pss->page for the next dirty bit in ramblock */ pss_find_next_dirty(pss); @@ -1567,8 +1573,7 @@ static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again) * We've been once around the RAM and haven't found anything. * Give up. */ - *again = false; - return false; + return PAGE_ALL_CLEAN; } if (!offset_in_ramblock(pss->block, ((ram_addr_t)pss->page) << TARGET_PAGE_BITS)) { @@ -1597,13 +1602,10 @@ static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again) } } /* Didn't find anything this time, but try again on the new block */ - *again = true; - return false; + return PAGE_TRY_AGAIN; } else { - /* Can go around again, but... */ - *again = true; - /* We've found something so probably don't need to */ - return true; + /* We've found something */ + return PAGE_DIRTY_FOUND; } } @@ -2562,19 +2564,23 @@ static int ram_find_and_save_block(RAMState *rs) pss_init(pss, rs->last_seen_block, rs->last_page); - do { + while (true) { if (!get_queued_page(rs, pss)) { /* priority queue empty, so just search for something dirty */ - bool again = true; - if (!find_dirty_block(rs, pss, &again)) { - if (!again) { + int res = find_dirty_block(rs, pss); + if (res != PAGE_DIRTY_FOUND) { + if (res == PAGE_ALL_CLEAN) { break; + } else if (res == PAGE_TRY_AGAIN) { + continue; } } - pages = ram_save_host_page(rs, pss); } - } while (!pages); - + pages = ram_save_host_page(rs, pss); + if (pages) { + break; + } + } rs->last_seen_block = pss->block; rs->last_page = pss->page; -- 2.39.1