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 28455C5AE59 for ; Wed, 28 May 2025 06:28:24 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uKAGO-0000Gb-5H; Wed, 28 May 2025 02:27:44 -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 1uKAGK-0000GT-Mu for qemu-devel@nongnu.org; Wed, 28 May 2025 02:27:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uKAGG-0003tu-6W for qemu-devel@nongnu.org; Wed, 28 May 2025 02:27:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748413653; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VXtSg9WBFgp4qV4aCgF7346HieNMOOTUPk14uioSezc=; b=auadEuWL6W/wKrUoWaSjvzZl+insndhTnFdiWt7pr5dl9NElL+lWGkJIryHEkV3Psx1KFn RrbHx03lERq/iYHyReBk9YzQLjWHN4WWCblcF/4cFK6aVSvVnkf1iCgkgPOo08aAaKzZWK bd54RswI+064GEB0vjMzDE4F2mEAh04= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-447-9kT_fB2yOCea59fCb5lPJA-1; Wed, 28 May 2025 02:27:29 -0400 X-MC-Unique: 9kT_fB2yOCea59fCb5lPJA-1 X-Mimecast-MFC-AGG-ID: 9kT_fB2yOCea59fCb5lPJA_1748413649 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8CA1A1955DB3; Wed, 28 May 2025 06:27:28 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.2]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F108E1956095; Wed, 28 May 2025 06:27:27 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 636B021E6768; Wed, 28 May 2025 08:27:25 +0200 (CEST) From: Markus Armbruster To: Peter Xu Cc: qemu-devel@nongnu.org, Juraj Marcin , Fabiano Rosas , "Dr . David Alan Gilbert" , Alexey Perevalov Subject: Re: [PATCH 02/11] migration/hmp: Fix postcopy-blocktime per-vCPU results In-Reply-To: <20250527215850.1271072-3-peterx@redhat.com> (Peter Xu's message of "Tue, 27 May 2025 17:58:41 -0400") References: <20250527215850.1271072-1-peterx@redhat.com> <20250527215850.1271072-3-peterx@redhat.com> Date: Wed, 28 May 2025 08:27:25 +0200 Message-ID: <878qmhjlma.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -49 X-Spam_score: -5.0 X-Spam_bar: ----- X-Spam_report: (-5.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.907, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=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 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? > + if ((++count % 10 == 0) && item) { > + monitor_printf(mon, "\n "); > + } > + } > + monitor_printf(mon, "\b\b]\n"); Uh, backspace? 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.