From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46193) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e4mxk-0000Rv-TF for qemu-devel@nongnu.org; Wed, 18 Oct 2017 07:56:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e4mxh-0002Dr-RA for qemu-devel@nongnu.org; Wed, 18 Oct 2017 07:56:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38512) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e4mxh-0002Di-L0 for qemu-devel@nongnu.org; Wed, 18 Oct 2017 07:56:37 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 76B8612B25 for ; Wed, 18 Oct 2017 11:56:36 +0000 (UTC) From: Juan Quintela In-Reply-To: <20171016160735.GF2252@work-vm> (David Alan Gilbert's message of "Mon, 16 Oct 2017 17:07:35 +0100") References: <20171004103933.7898-1-quintela@redhat.com> <20171004103933.7898-5-quintela@redhat.com> <20171016160735.GF2252@work-vm> Reply-To: quintela@redhat.com Date: Wed, 18 Oct 2017 13:56:31 +0200 Message-ID: <8760bcmzyo.fsf@secure.laptop> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH 4/6] tests: Add migration xbzrle test List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org, lvivier@redhat.com, peterx@redhat.com "Dr. David Alan Gilbert" wrote: > * Juan Quintela (quintela@redhat.com) wrote: >> Signed-off-by: Juan Quintela > +static void test_xbzrle(const char *uri) >> +{ >> + QTestState *from, *to; >> + >> + test_migrate_start(&from, &to, uri); >> + >> + /* We want to pick a speed slow enough that the test completes >> + * quickly, but that it doesn't complete precopy even on a slow >> + * machine, so also set the downtime. >> + */ >> + /* 100 ms */ >> + migrate_set_parameter(from, "downtime-limit", "100"); >> + /* 1MB/s slow*/ >> + migrate_set_parameter(from, "max-bandwidth", "100000000"); >> + >> + migrate_set_cache_size(from, "50000000"); > > Why 50MB? I guess this is an interesting test; the program > dirties 100MB of RAM repeatedly, one byte/page. So 50MB is probably > not much use becuase it'll thrash. No good reason. What I want (tm): - if you have fast hardware, test is as fast as it can - if you don't have fast hardware (or very overloaded), it don't fail My current idea is: - using 1GB/s for speed - using downtime = 1ms when I want to wait for migration not converge - using downtime = 300ms when I want it to finish I am open to other numbers. >> + migrate_set_capability(from, "xbzrle", "true"); >> + migrate_set_capability(to, "xbzrle", "true"); >> + /* Wait for the first serial output from the source */ >> + wait_for_serial("src_serial"); >> + >> + migrate(from, uri); >> + >> + wait_for_migration_pass(from); >> + >> + /* 1GB/s now it should converge */ >> + migrate_set_parameter(from, "max-bandwidth", "1000000000"); > > I wonder about doing a set_cache_size 150MB here, with a delay before > the max-bandwidht? If we're lucky at 150MB it'll start actually using > the XBZRLE compression. > >> + if (!got_stop) { >> + qtest_qmp_eventwait(from, "STOP"); >> + } >> + qtest_qmp_eventwait(to, "RESUME"); >> + >> + wait_for_serial("dest_serial"); >> + wait_for_migration_complete(from); >> + >> + test_migrate_end(from, to); > > Extract xbzrle stats? Thinking about that. I actually would want to test that when I set something, read it back that it is what I setted. I gues I would use a similar trick to what you do to get the pass number. Later, Juan.