From: Steven Rostedt <rostedt@goodmis.org>
To: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v2 3/2] trace-cmd: Optimize the logic of reset_cpu_mask()
Date: Thu, 3 Oct 2019 10:44:53 -0400 [thread overview]
Message-ID: <20191003104453.51fbdadb@gandalf.local.home> (raw)
In-Reply-To: <20191001145740.8866-1-tz.stoyanov@gmail.com>
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Change the logic of reset_cpu_mask() to be a little more condensed, and also
move the buffer onto the stack and eliminate the warning message as we no
longer need to use malloc.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
tracecmd/trace-record.c | 25 ++++++-------------------
1 file changed, 6 insertions(+), 19 deletions(-)
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 6f3520cc..cfe67f90 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -4100,27 +4100,14 @@ static void reset_cpu_mask(void)
{
struct buffer_instance *instance;
int cpus = count_cpus();
- int fullwords;
- char *buf;
- int bits;
- int len;
+ int fullwords = (cpus - 1) / 32;
+ int bits = (cpus - 1) % 32 + 1;
+ int len = (fullwords + 1) * 9;
+ char buf[len + 1];
- fullwords = cpus / 32;
- bits = cpus % 32;
- len = (fullwords + 1) * 9;
-
- buf = malloc(len + 1);
- if (!buf) {
- warning("Unable to allocate %d bytes for cpu mask", len + 1);
- return;
- }
buf[0] = '\0';
- if (bits) {
- sprintf(buf, "%x", (1 << bits) - 1);
- } else if (fullwords) {
- strcat(buf, "ffffffff");
- fullwords--;
- }
+
+ sprintf(buf, "%x", (unsigned int)((1ULL << bits) - 1));
while (fullwords-- > 0)
strcat(buf, ",ffffffff");
--
2.20.1
prev parent reply other threads:[~2019-10-03 14:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-01 14:57 [PATCH v2 0/2] Reset CPU mask Tzvetomir Stoyanov (VMware)
2019-10-01 14:57 ` [PATCH v2 1/2] trace-cmd: Reset CPU mask after setting it in trace-cmd record with option -M Tzvetomir Stoyanov (VMware)
2019-10-01 14:57 ` [PATCH v2 2/2] trace-cmd: Reset CPU mask to its default value with "trace-cmd reset" Tzvetomir Stoyanov (VMware)
2019-10-01 15:32 ` Steven Rostedt
2019-10-01 15:37 ` Tzvetomir Stoyanov
2019-10-01 15:45 ` Steven Rostedt
2019-10-03 14:44 ` Steven Rostedt [this message]
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