From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4209E38D6A4 for ; Thu, 16 Apr 2026 08:41:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776328912; cv=none; b=PKtGUkuJSABQgau+VEP5JQROXkoR/1a1exU7iFAJUlpcjZeJFFXSBGZ2KOd4culWxo5SgOTVsXmAhsHiQW3u67uIpfZQHmd+t9e26mszJ5+zU64gIgBq47rHE83X8q9RdEEBrOjIw0p+4iURcsITcy5qEMxlhKuuv/w51gM/BXo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776328912; c=relaxed/simple; bh=CgwhL3BOTkEXTJn8VDvcHuTRnTwP5WMWhEUfbrNCLLU=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=Zmeub4Y6VYsLLYrBNrNhdsLbtEd1WKC23iUnD3dNori7ODiiVWNZwZhE3vghW1UU+uGCN1/BR1X98PZU2RbhBzCEEB/lx5P8rf8kIA7eOvUEs0O3fM03T8K3d+00io9MzIWYODH6ZodTBgvhYMA0YyHyQLylmbfS1i9rCL3Q0Fc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oZR2TeRR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oZR2TeRR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11150C2BCB5; Thu, 16 Apr 2026 08:41:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776328912; bh=CgwhL3BOTkEXTJn8VDvcHuTRnTwP5WMWhEUfbrNCLLU=; h=Date:From:To:Cc:Subject:References:From; b=oZR2TeRRWyicNF2VING0Dw1GzqHgqCdfnVSpUZdYZEWNdXO2jNzHD+0t37P3nELTp jWlDl1cRCsogzuhGt0M7eWtQs8d7wuzDN8qsL+nxz2sHHrl2FUYZV4sx16l1WIeheh Lpr05EwoQtjRqnPhyERUisP9uSS5BjOMJVDqEpVfki2UUjSeHZSzxA6cZwmXdWSxb7 7DVK2dYYUDatpy3RbPwEHUilSEZtya/YIrANiJR9nnvshsPYSi4Z+8JPtXTr61L6Yx GoTueSlfVIGkbariYvTmQmVnRsQdzHCSyCvmGnDDXtVCFtRnAbSJdhwUcPVkCoM1v4 2BKcvnGjJdlAw== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1wDIJq-00000005awP-26Mv; Thu, 16 Apr 2026 04:43:26 -0400 Message-ID: <20260416084326.371411112@kernel.org> User-Agent: quilt/0.69 Date: Thu, 16 Apr 2026 04:42:58 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Tom Zanussi Subject: [for-next][PATCH 4/5] tracing: Fix fully-qualified variable reference printing in histograms References: <20260416084254.980129867@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Tom Zanussi The syntax for fully-qualified variable references in histograms is subsys.event.$var, which is parsed correctly, but not displayed correctly when printing a histogram spec. The current code puts the $ reference at the beginning of the fully-qualified variable name i.e. $subsys.event.var, which is incorrect. Before: trigger info: hist:keys=next_comm:vals=hitcount:wakeup_lat=common_timestamp.usecs-$sched.sched_wakeup.ts0: ... After: trigger info: hist:keys=next_comm:vals=hitcount:wakeup_lat=common_timestamp.usecs-sched.sched_wakeup.$ts0: ... Link: https://patch.msgid.link/5dee9a86d062a4dd68c2214f3d90ac93811e1951.1776112478.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_hist.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index b2b675c7d663..0dbbf6cca9bc 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1361,9 +1361,12 @@ static const char *hist_field_name(struct hist_field *field, field->flags & HIST_FIELD_FL_VAR_REF) { if (field->system) { static char full_name[MAX_FILTER_STR_VAL]; + static char *fmt; int len; - len = snprintf(full_name, sizeof(full_name), "%s.%s.%s", + fmt = field->flags & HIST_FIELD_FL_VAR_REF ? "%s.%s.$%s" : "%s.%s.%s"; + + len = snprintf(full_name, sizeof(full_name), fmt, field->system, field->event_name, field->name); if (len >= sizeof(full_name)) @@ -1742,9 +1745,10 @@ static const char *get_hist_field_flags(struct hist_field *hist_field) static void expr_field_str(struct hist_field *field, char *expr) { - if (field->flags & HIST_FIELD_FL_VAR_REF) - strcat(expr, "$"); - else if (field->flags & HIST_FIELD_FL_CONST) { + if (field->flags & HIST_FIELD_FL_VAR_REF) { + if (!field->system) + strcat(expr, "$"); + } else if (field->flags & HIST_FIELD_FL_CONST) { char str[HIST_CONST_DIGITS_MAX]; snprintf(str, HIST_CONST_DIGITS_MAX, "%llu", field->constant); @@ -6156,7 +6160,8 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) else if (field_name) { if (hist_field->flags & HIST_FIELD_FL_VAR_REF || hist_field->flags & HIST_FIELD_FL_ALIAS) - seq_putc(m, '$'); + if (!hist_field->system) + seq_putc(m, '$'); seq_printf(m, "%s", field_name); } else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP) seq_puts(m, "common_timestamp"); -- 2.51.0