From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39654) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ctcvF-0007XV-0D for qemu-devel@nongnu.org; Thu, 30 Mar 2017 12:27:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ctcvA-0000qN-Tv for qemu-devel@nongnu.org; Thu, 30 Mar 2017 12:27:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46672) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ctcvA-0000ps-LW for qemu-devel@nongnu.org; Thu, 30 Mar 2017 12:27:36 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B5595C037F76 for ; Thu, 30 Mar 2017 16:27:35 +0000 (UTC) From: Juan Quintela In-Reply-To: <20170329180239.GG2501@work-vm> (David Alan Gilbert's message of "Wed, 29 Mar 2017 19:02:39 +0100") References: <20170323204544.12015-1-quintela@redhat.com> <20170323204544.12015-38-quintela@redhat.com> <20170329180239.GG2501@work-vm> Reply-To: quintela@redhat.com Date: Thu, 30 Mar 2017 18:27:32 +0200 Message-ID: <87zig2logb.fsf@secure.mitica> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH 37/51] ram: Move compression_switch to RAMState List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org "Dr. David Alan Gilbert" wrote: > * Juan Quintela (quintela@redhat.com) wrote: >> Rename it to preffer_xbzrle that is a more descriptive name. >> >> Signed-off-by: Juan Quintela >> --- >> migration/ram.c | 9 +++++---- >> 1 file changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/migration/ram.c b/migration/ram.c >> index 6a39704..591cf89 100644 >> --- a/migration/ram.c >> +++ b/migration/ram.c >> @@ -217,6 +217,9 @@ struct RAMState { >> uint64_t dirty_pages_rate; >> /* Count of requests incoming from destination */ >> uint64_t postcopy_requests; >> + /* Should we move to xbzrle after the 1st round >> + of compression */ >> + bool preffer_xbzrle; > > That's 'prefer' - however, do we need it at all? > How about just replacing it by: > !ram_bulk_stage && migrate_use_xbzrle() > > would that work? if (migrate_use_compression()) && (rs->ram_bulk_stage || !migrate_use_xbzrle()) { res = ram_save_compressed_page(rs, ms, pss, last_stage); To remove the two !(!...) I changed to this. Later, Juan. > > Dave > >> /* protects modification of the bitmap */ >> QemuMutex bitmap_mutex; >> /* Ram Bitmap protected by RCU */ >> @@ -335,7 +338,6 @@ 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; >> @@ -419,7 +421,6 @@ 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); >> @@ -1091,7 +1092,7 @@ 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; >> + rs->preffer_xbzrle = true; >> } >> } >> /* Didn't find anything this time, but try again on the new block */ >> @@ -1323,7 +1324,7 @@ 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 (!rs->preffer_xbzrle && migrate_use_compression()) { >> res = ram_save_compressed_page(rs, ms, pss, last_stage); >> } else { >> res = ram_save_page(rs, ms, pss, last_stage); >> -- >> 2.9.3 >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK