From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 903ACC3ABB2 for ; Wed, 28 May 2025 15:09:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uKIOb-0008Dh-Cl; Wed, 28 May 2025 11:08:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uKIOY-0008DL-AY for qemu-devel@nongnu.org; Wed, 28 May 2025 11:08:42 -0400 Received: from mx.treblig.org ([2a00:1098:5b::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uKIOW-0005Il-Gh for qemu-devel@nongnu.org; Wed, 28 May 2025 11:08:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=treblig.org ; s=bytemarkmx; h=Content-Type:MIME-Version:Message-ID:Subject:From:Date:From :Subject; bh=A444BULaFGdGRdAIQzV8pqnVG/O4oosLAevwi537/wk=; b=kNzdNRRs/Pf2x7Ux KJQ+xAWdF7Cs4fKhy2YV3aADt9v73GeTUJE1MLqTfyzZaytYyU2ZFiUJZe5peCANDF6i+Yx32Anjc s+BQM4TlSJRRswdN1fSWXC3S59WazRLnqRiDXpttR/KX31KtdMff/MkrG+k49fPv0sUx+nj1v16ZI WsIhL2KnAgozBHxaWG60YLxcJWius4lSDs1yq9gMYY5EulGeKoZvBPiy2UOfduasARgzqQgGfTNlo wYeI6SUXYNCl7sAU8g4Q8Voj9hWXw+SdJ7YJZu8T0WFgKZba36X2/uAWwDgZucM7AujXKtclfSTXM toH2CgMC0oZh6+RfHQ==; Received: from dg by mx.treblig.org with local (Exim 4.96) (envelope-from ) id 1uKIOU-006Dk0-28; Wed, 28 May 2025 15:08:38 +0000 Date: Wed, 28 May 2025 15:08:38 +0000 From: "Dr. David Alan Gilbert" To: Markus Armbruster Cc: Peter Xu , qemu-devel@nongnu.org, Juraj Marcin , Fabiano Rosas , Alexey Perevalov Subject: Re: [PATCH 02/11] migration/hmp: Fix postcopy-blocktime per-vCPU results Message-ID: References: <20250527215850.1271072-1-peterx@redhat.com> <20250527215850.1271072-3-peterx@redhat.com> <878qmhjlma.fsf@pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <878qmhjlma.fsf@pond.sub.org> X-Chocolate: 70 percent or better cocoa solids preferably X-Operating-System: Linux/6.1.0-34-amd64 (x86_64) X-Uptime: 15:08:12 up 30 days, 23:21, 1 user, load average: 0.03, 0.02, 0.00 User-Agent: Mutt/2.2.12 (2023-09-09) Received-SPF: pass client-ip=2a00:1098:5b::1; envelope-from=dg@treblig.org; helo=mx.treblig.org 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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 * Markus Armbruster (armbru@redhat.com) wrote: > Peter Xu writes: > > > Unfortunately, it was never correctly shown.. > > > > This is only found when I started to look into making the blocktime feature > > more useful (so as to avoid using bpftrace, even though I'm not sure which > > one will be harder to use..). > > > > So the old dump would look like this: > > > > Postcopy vCPU Blocktime: 0-1,4,10,21,33,46,48,59 > > > > Even though there're actually 40 vcpus, and the string will merge same > > elements and also sort them. > > > > To fix it, simply loop over the uint32List manually. Now it looks like: > > > > Postcopy vCPU Blocktime (ms): > > [15, 0, 0, 43, 29, 34, 36, 29, 37, 41, > > 33, 37, 45, 52, 50, 38, 40, 37, 40, 49, > > 40, 35, 35, 35, 81, 19, 18, 19, 18, 30, > > 22, 3, 0, 0, 0, 0, 0, 0, 0, 0] > > > > Cc: Dr. David Alan Gilbert > > Cc: Alexey Perevalov > > Cc: Markus Armbruster > > Signed-off-by: Peter Xu > > --- > > migration/migration-hmp-cmds.c | 23 ++++++++++++++--------- > > 1 file changed, 14 insertions(+), 9 deletions(-) > > > > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c > > index 367ff6037f..3cf890b887 100644 > > --- a/migration/migration-hmp-cmds.c > > +++ b/migration/migration-hmp-cmds.c > > @@ -208,15 +208,20 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict) > > } > > > > if (info->has_postcopy_vcpu_blocktime) { > > - Visitor *v; > > - char *str; > > - v = string_output_visitor_new(false, &str); > > - visit_type_uint32List(v, NULL, &info->postcopy_vcpu_blocktime, > > - &error_abort); > > - visit_complete(v, &str); > > - monitor_printf(mon, "Postcopy vCPU Blocktime: %s\n", str); > > - g_free(str); > > - visit_free(v); > > + uint32List *item = info->postcopy_vcpu_blocktime; > > + int count = 0; > > + > > + monitor_printf(mon, "Postcopy vCPU Blocktime (ms): \n ["); > > + > > + while (item) { > > + monitor_printf(mon, "%"PRIu32", ", item->value); > > + item = item->next; > > + /* Each line 10 vcpu results, newline if there's more */ > > The list can be arbitrarily long? One per vCPU, so a small arbitrary. > > + if ((++count % 10 == 0) && item) { > > + monitor_printf(mon, "\n "); > > + } > > + } > > + monitor_printf(mon, "\b\b]\n"); > > Uh, backspace? Agreed! Dave > I usually do something like > > sep = ""; > for (...) { > printf("%s...", sep, ...); > sep = ", " > } > > To add line breaks, I'd use something like > > sep = ... ? ", " : ",\n"; > > > } > > > > out: > > The less the string visitors are used, the happier I am. > -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/