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 86F99C433F5 for ; Tue, 24 May 2022 13:11:54 +0000 (UTC) Received: from localhost ([::1]:38012 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ntUKH-000813-Bp for qemu-devel@archiver.kernel.org; Tue, 24 May 2022 09:11:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59888) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ntUHT-0005yI-7b for qemu-devel@nongnu.org; Tue, 24 May 2022 09:08:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:22257) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ntUHP-0001a3-RW for qemu-devel@nongnu.org; Tue, 24 May 2022 09:08:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653397734; 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=t5kM8z94aqYdCtQdRFA4E3uOxiCi4S2Gnh/LNIY/9LY=; b=D5Um3yDNWXQL7BuKoxRaWiAWB4fwmP03kfFDLWz4iIDgMx46g2gmzRTvrWF4xTsI1QvSt3 idwvGxCSeOXszASmu0nVrgqgJDXcNMBYZni2BCy9LPmYpflCrMYP3QVuz5+EdtxZ0ejlNR f+lq/+bdDDFoCqNma/uWAzm+TOTCNxE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-450-_D4PSFMNNxmT6C9iqwAdeQ-1; Tue, 24 May 2022 09:08:53 -0400 X-MC-Unique: _D4PSFMNNxmT6C9iqwAdeQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CB6593C1618C; Tue, 24 May 2022 13:08:52 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.36.112.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 88C7840D1B98; Tue, 24 May 2022 13:08:52 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 5138D21E6906; Tue, 24 May 2022 15:08:51 +0200 (CEST) From: Markus Armbruster To: Paolo Bonzini Cc: qemu-devel@nongnu.org, Mark Kanda Subject: Re: [PATCH 7/8] qmp: add filtering of statistics by name References: <20220523150509.349412-1-pbonzini@redhat.com> <20220523150722.349700-1-pbonzini@redhat.com> <20220523150722.349700-7-pbonzini@redhat.com> Date: Tue, 24 May 2022 15:08:51 +0200 In-Reply-To: <20220523150722.349700-7-pbonzini@redhat.com> (Paolo Bonzini's message of "Mon, 23 May 2022 17:07:21 +0200") Message-ID: <87mtf7w00s.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" Paolo Bonzini writes: > Allow retrieving only a subset of statistics. This can be useful > for example in order to plot a subset of the statistics many times > a second. > > KVM publishes ~40 statistics for each vCPU on x86; retrieving and > serializing all of them would be useless > > Another use will be in HMP in the following patch; implementing the > filter in the backend is easy enough that it was deemed okay to make > this a public interface. > > Example: > > { "execute": "query-stats", > "arguments": { > "target": "vcpu", > "vcpus": [ "/machine/unattached/device[2]", > "/machine/unattached/device[4]" ], > "providers": [ > { "provider": "kvm", > "names": [ "l1d_flush", "exits" ] } } } > > { "return": { > "vcpus": [ > { "path": "/machine/unattached/device[2]" > "providers": [ > { "provider": "kvm", > "stats": [ { "name": "l1d_flush", "value": 41213 }, > { "name": "exits", "value": 74291 } ] } ] }, > { "path": "/machine/unattached/device[4]" > "providers": [ > { "provider": "kvm", > "stats": [ { "name": "l1d_flush", "value": 16132 }, > { "name": "exits", "value": 57922 } ] } ] } ] } } > > Extracted from a patch by Mark Kanda. > > Signed-off-by: Paolo Bonzini > --- > v3->v4: handle empty filter early by avoiding the query altogether > > accel/kvm/kvm-all.c | 17 +++++++++++------ > include/monitor/stats.h | 4 ++-- > monitor/qmp-cmds.c | 16 +++++++++++++--- > qapi/stats.json | 6 +++++- > 4 files changed, 31 insertions(+), 12 deletions(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 461b6cf927..a61d17719e 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -2311,7 +2311,7 @@ bool kvm_dirty_ring_enabled(void) > return kvm_state->kvm_dirty_ring_size ? true : false; > } > > -static void query_stats_cb(StatsResultList **result, StatsTarget target, > +static void query_stats_cb(StatsResultList **result, StatsTarget target, strList *names, Long line. > strList *targets, Error **errp); > static void query_stats_schemas_cb(StatsSchemaList **result, Error **errp); > > @@ -3713,6 +3713,7 @@ typedef struct StatsArgs { > StatsResultList **stats; > StatsSchemaList **schema; > } result; > + strList *names; > Error **errp; > } StatsArgs; > > @@ -3926,7 +3927,7 @@ static StatsDescriptors *find_stats_descriptors(StatsTarget target, int stats_fd > return descriptors; > } > > -static void query_stats(StatsResultList **result, StatsTarget target, > +static void query_stats(StatsResultList **result, StatsTarget target, strList *names, Long line. > int stats_fd, Error **errp) > { > struct kvm_stats_desc *kvm_stats_desc; > @@ -3969,6 +3970,9 @@ static void query_stats(StatsResultList **result, StatsTarget target, > > /* Add entry to the list */ > stats = (void *)stats_data + pdesc->offset; > + if (!apply_str_list_filter(pdesc->name, names)) { > + continue; > + } > stats_list = add_kvmstat_entry(pdesc, stats, stats_list, errp); > } > > @@ -4030,8 +4034,8 @@ static void query_stats_vcpu(CPUState *cpu, run_on_cpu_data data) > error_propagate(kvm_stats_args->errp, local_err); > return; > } > - query_stats(kvm_stats_args->result.stats, STATS_TARGET_VCPU, stats_fd, > - kvm_stats_args->errp); > + query_stats(kvm_stats_args->result.stats, STATS_TARGET_VCPU, > + kvm_stats_args->names, stats_fd, kvm_stats_args->errp); > close(stats_fd); > } > > @@ -4052,7 +4056,7 @@ static void query_stats_schema_vcpu(CPUState *cpu, run_on_cpu_data data) > } > > static void query_stats_cb(StatsResultList **result, StatsTarget target, > - strList *targets, Error **errp) > + strList *names, strList *targets, Error **errp) > { > KVMState *s = kvm_state; > CPUState *cpu; > @@ -4066,7 +4070,7 @@ static void query_stats_cb(StatsResultList **result, StatsTarget target, > error_setg(errp, "KVM stats: ioctl failed"); > return; > } > - query_stats(result, target, stats_fd, errp); > + query_stats(result, target, names, stats_fd, errp); > close(stats_fd); > break; > } > @@ -4074,6 +4078,7 @@ static void query_stats_cb(StatsResultList **result, StatsTarget target, > { > StatsArgs stats_args; > stats_args.result.stats = result; > + stats_args.names = names; > stats_args.errp = errp; > CPU_FOREACH(cpu) { > if (!apply_str_list_filter(cpu->parent_obj.canonical_path, targets)) { > diff --git a/include/monitor/stats.h b/include/monitor/stats.h > index 840c4ed08e..88f046f568 100644 > --- a/include/monitor/stats.h > +++ b/include/monitor/stats.h > @@ -11,8 +11,8 @@ > #include "qapi/qapi-types-stats.h" > > typedef void StatRetrieveFunc(StatsResultList **result, StatsTarget target, > - strList *targets, Error **errp); > -typedef void SchemaRetrieveFunc(StatsSchemaList **result, Error **errp); > + strList *names, strList *targets, Error **errp); > +typedef void SchemaRetrieveFunc(StatsSchemaList **, Error **); Did you drop the parameter names intentionally? > > /* > * Register callbacks for the QMP query-stats command. > diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c > index 7be0e7414a..e822f1b0a9 100644 > --- a/monitor/qmp-cmds.c > +++ b/monitor/qmp-cmds.c > @@ -467,15 +467,24 @@ void add_stats_callbacks(StatsProvider provider, > } > > static bool stats_provider_requested(StatsProvider provider, > - StatsFilter *filter) > + StatsFilter *filter, > + strList **p_names) > { > StatsRequestList *request; > > + *p_names = NULL; > if (!filter->has_providers) { > return true; > } > for (request = filter->providers; request; request = request->next) { > if (request->value->provider == provider) { > + if (request->value->has_names) { > + if (!request->value->names) { > + /* No names allowed is the same as skipping the provider. */ Long line. > + return false; Any other elements of filter->providers that match @provider will be silently ignored. Is this what you want? Uh, do we leak @p_names if earlier elements matched? > + } > + *p_names = request->value->names; > + } > return true; > } > } > @@ -506,8 +515,9 @@ StatsResultList *qmp_query_stats(StatsFilter *filter, Error **errp) > } > > QTAILQ_FOREACH(entry, &stats_callbacks, next) { > - if (stats_provider_requested(entry->provider, filter)) { > - entry->stats_cb(&stats_results, filter->target, targets, errp); > + strList *names = NULL; > + if (stats_provider_requested(entry->provider, filter, &names)) { > + entry->stats_cb(&stats_results, filter->target, names, targets, errp); Brain cramp (broken night)... where is @names freed? Long line. > if (*errp) { > qapi_free_StatsResultList(stats_results); > return NULL; > diff --git a/qapi/stats.json b/qapi/stats.json > index b75bb86124..2dbf188d36 100644 > --- a/qapi/stats.json > +++ b/qapi/stats.json > @@ -74,11 +74,14 @@ > # Indicates a set of statistics that should be returned by query-stats. > # > # @provider: provider for which to return statistics. > + > +# @names: statistics to be returned (all if omitted). > # > # Since: 7.1 > ## > { 'struct': 'StatsRequest', > - 'data': { 'provider': 'StatsProvider' } } > + 'data': { 'provider': 'StatsProvider', > + '*names': [ 'str' ] } } > > ## > # @StatsVCPUFilter: > @@ -98,6 +101,7 @@ > # that target: > # - which vCPUs to request statistics for > # - which provider to request statistics from Should this be "which providers"? > +# - which values to return within each provider This is member @provider sub-member @names. Hmm. "which named values to return"? > # > # Since: 7.1 > ##