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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4B0BCA0ECA for ; Tue, 12 Sep 2023 12:20:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231127AbjILMUY (ORCPT ); Tue, 12 Sep 2023 08:20:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235103AbjILMUV (ORCPT ); Tue, 12 Sep 2023 08:20:21 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DC08810D2 for ; Tue, 12 Sep 2023 05:19:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694521170; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aYCud5TTTXD52ydxJR0TroJhA01q5jw7zVV5G1QYWwM=; b=O1aO5MHf2TVPDbyd/Ar48bQEWIxawhXsFSp7i4EVxCGzGGjdE8ChynbHPRNexlgRqKkGTV DK3The6i9oUv9G0/iI+HDI7x43Xos4k9iPwrqeaWEm+Qg3rVoLXupaSK78c7cBlLLbdX4o U8+ZGyyzw5iCMYwvFHmpLoZW5UH7S8I= Received: from mimecast-mx02.redhat.com (mx-ext.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-625-2xY1DNxtNfabCLeF1FhJqw-1; Tue, 12 Sep 2023 08:19:29 -0400 X-MC-Unique: 2xY1DNxtNfabCLeF1FhJqw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 154193800BCD; Tue, 12 Sep 2023 12:19:29 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.45.226.192]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5994F1006E0B; Tue, 12 Sep 2023 12:19:28 +0000 (UTC) From: vmolnaro@redhat.com To: linux-perf-users@vger.kernel.org, acme@kernel.org, acme@redhat.com Cc: mpetlan@redhat.com Subject: [PATCH 2/2] perf test stat+shadow_stat.sh: Add threshold for rounding errors Date: Tue, 12 Sep 2023 14:19:26 +0200 Message-ID: <20230912121926.12111-2-vmolnaro@redhat.com> In-Reply-To: <20230912121926.12111-1-vmolnaro@redhat.com> References: <20230912121926.12111-1-vmolnaro@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org From: Veronika Molnarova The test was failing in specific scenarios due to imperfection of FP arithmetics. The `bc` command wasn't correctly rounding the result of division causing the failure. Replace the `bc` with `awk` which should work with more decimal places and add a threshold to catch any possible rounding errors. The acceptable rounding error is set to 0.01 when the test passes with a warning message. --- tools/perf/tests/shell/stat+shadow_stat.sh | 30 +++++++++++++++++----- 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/tools/perf/tests/shell/stat+shadow_stat.sh b/tools/perf/tests/shell/stat+shadow_stat.sh index 0e9cba84e75..73c990fe5ee 100755 --- a/tools/perf/tests/shell/stat+shadow_stat.sh +++ b/tools/perf/tests/shell/stat+shadow_stat.sh @@ -4,6 +4,8 @@ set -e +TRESHOLD=0.015 + # skip if system-wide mode is forbidden perf stat -a true > /dev/null 2>&1 || exit 2 @@ -33,10 +35,18 @@ test_global_aggr() fi # use printf for rounding and a leading zero - res=`printf "%.2f" "$(echo "scale=6; $num / $cyc" | bc -q)"` + res=`echo $num $cyc | awk '{printf "%.2f", $1 / $2}'` if [ "$ipc" != "$res" ]; then - echo "IPC is different: $res != $ipc ($num / $cyc)" - exit 1 + # check the difference from the real result for FP imperfections + diff=`echo $ipc $res $TRESHOLD | \ + awk '{x = ($1 - $2) < 0 ? ($2 - $1) : ($1 - $2); print (x > $3)}'` + + if [ $diff -eq 1 ]; then + echo "IPC is different: $res != $ipc ($num / $cyc)" + exit 1 + fi + + echo "Warning: Difference of IPC is under the treshold" fi done } @@ -67,10 +77,18 @@ test_no_aggr() fi # use printf for rounding and a leading zero - res=`printf "%.2f" "$(echo "scale=6; $num / $cyc" | bc -q)"` + res=`echo $num $cyc | awk '{printf "%.2f", $1 / $2}'` if [ "$ipc" != "$res" ]; then - echo "IPC is different for $cpu: $res != $ipc ($num / $cyc)" - exit 1 + # check difference from the real result for FP imperfections + diff=`echo $ipc $res $TRESHOLD | \ + awk '{x = ($1 - $2) < 0 ? ($2 - $1) : ($1 - $2); print (x > $3)}'` + + if [ $diff -eq 1 ]; then + echo "IPC is different: $res != $ipc ($num / $cyc)" + exit 1 + fi + + echo "Warning: Difference of IPC is under the treshold" fi done } -- 2.41.0