From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50832) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxnCc-000744-HI for qemu-devel@nongnu.org; Tue, 11 Apr 2017 00:14:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxnCX-0000NX-JN for qemu-devel@nongnu.org; Tue, 11 Apr 2017 00:14:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52330) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cxnCX-0000NL-As for qemu-devel@nongnu.org; Tue, 11 Apr 2017 00:14:45 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3A8A73B755 for ; Tue, 11 Apr 2017 04:14:44 +0000 (UTC) Date: Tue, 11 Apr 2017 12:14:38 +0800 From: Peter Xu Message-ID: <20170411041438.GE2313@pxdev.xzpeter.org> References: <20170406130913.2232-1-quintela@redhat.com> <20170406130913.2232-41-quintela@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170406130913.2232-41-quintela@redhat.com> Subject: Re: [Qemu-devel] [PATCH 40/54] ram: Remove compression_switch and inline its logic List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela Cc: qemu-devel@nongnu.org, dgilbert@redhat.com On Thu, Apr 06, 2017 at 03:08:59PM +0200, Juan Quintela wrote: > We can calculate its value, so not create a varible for it. > > Signed-off-by: Juan Quintela > > -- > > After Peter and Dave review, I dropped the variable and just inlined > the condition. > > Later, Juan. > > Signed-off-by: Juan Quintela > --- > migration/ram.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/migration/ram.c b/migration/ram.c > index 14d54fd..5dfc9bd 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -336,7 +336,6 @@ static QemuCond comp_done_cond; > /* The empty QEMUFileOps will be used by file in CompressParam */ > static const QEMUFileOps empty_ops = { }; > > -static bool compression_switch; > static DecompressParam *decomp_param; > static QemuThread *decompress_threads; > static QemuMutex decomp_done_lock; > @@ -420,7 +419,6 @@ void migrate_compress_threads_create(void) > if (!migrate_use_compression()) { > return; > } > - compression_switch = true; > thread_count = migrate_compress_threads(); > compress_threads = g_new0(QemuThread, thread_count); > comp_param = g_new0(CompressParam, thread_count); > @@ -1092,7 +1090,6 @@ static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, > * point. In theory, xbzrle can do better than compression. > */ > flush_compressed_data(rs); > - compression_switch = false; > } > } > /* Didn't find anything this time, but try again on the new block */ > @@ -1326,7 +1323,14 @@ static int ram_save_target_page(RAMState *rs, MigrationState *ms, > /* Check the pages is dirty and if it is send it */ > if (migration_bitmap_clear_dirty(rs, dirty_ram_abs)) { > unsigned long *unsentmap; > - if (compression_switch && migrate_use_compression()) { > + /* > + * If xbzrle is on, stop using the data compression after first > + * round of migration even if compression is enabled. In theory, > + * xbzrle can do better than compression. > + */ > + > + if (migrate_use_compression()) ^ is this a superfluous ")"? > + && (rs->ram_bulk_stage || !migrate_use_xbzrle()) { > res = ram_save_compressed_page(rs, ms, pss, last_stage); > } else { > res = ram_save_page(rs, ms, pss, last_stage); > -- > 2.9.3 Thanks, -- peterx