From: "Slavomir Kaslev (VMware)" <slavomir.kaslev@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v12 10/13] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified
Date: Tue, 18 Jun 2019 17:44:52 +0300 [thread overview]
Message-ID: <20190618144455.3954-11-slavomir.kaslev@gmail.com> (raw)
In-Reply-To: <20190618144455.3954-1-slavomir.kaslev@gmail.com>
From: Slavomir Kaslev <kaslevs@vmware.com>
When no number of guest CPUs is provided with the -c flag to `trace-cmd
setup-guest`, try to autodetect it using virsh for libvirt managed guests.
Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
tracecmd/trace-setup-guest.c | 21 +++++++++++++++++++++
tracecmd/trace-usage.c | 2 +-
2 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c
index a6f58dc..a55a37d 100644
--- a/tracecmd/trace-setup-guest.c
+++ b/tracecmd/trace-setup-guest.c
@@ -93,6 +93,24 @@ static int make_guest_fifos(const char *guest, int nr_cpus, mode_t mode)
return ret;
}
+static int get_guest_cpu_count(const char *guest)
+{
+ const char *cmd_fmt = "virsh vcpucount --maximum '%s' 2>/dev/null";
+ int nr_cpus = -1;
+ char cmd[1024];
+ FILE *f;
+
+ snprintf(cmd, sizeof(cmd), cmd_fmt, guest);
+ f = popen(cmd, "r");
+ if (!f)
+ return -errno;
+
+ fscanf(f, "%d", &nr_cpus);
+ pclose(f);
+
+ return nr_cpus;
+}
+
static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid)
{
gid_t save_egid;
@@ -171,6 +189,9 @@ void trace_setup_guest(int argc, char **argv)
guest = argv[optind+1];
+ if (nr_cpus <= 0)
+ nr_cpus = get_guest_cpu_count(guest);
+
if (nr_cpus <= 0)
pdie("invalid number of cpus for guest %s", guest);
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 0d1b58e..a2a520c 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -251,7 +251,7 @@ static struct usage_help usage_help[] = {
{
"setup-guest",
"create FIFOs for tracing guest VMs",
- " %s setup-guest -c cpus[-p perm][-g group] guest\n"
+ " %s setup-guest [-c cpus][-p perm][-g group] guest\n"
" -c number of guest virtual CPUs\n"
" -p FIFOs permissions (default: 0660)\n"
" -g FIFOs group owner\n"
--
2.20.1
next prev parent reply other threads:[~2019-06-18 14:45 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-18 14:44 [PATCH v12 00/13] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 01/13] trace-cmd: Make ports unsigned int Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 02/13] trace-cmd: Detect if vsockets are available Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 03/13] trace-cmd: Add tracecmd_create_recorder_virt() function Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 04/13] trace-cmd: Add VM tracing protocol messages Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 05/13] trace-cmd: Add buffer instance flags for tracing in guest and agent context Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 06/13] trace-cmd: Add VM kernel tracing over vsockets transport Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 07/13] trace-cmd: Use splice(2) for vsockets if available Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 08/13] trace-cmd: Switch stop recording signal to SIGUSR1 Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 09/13] trace-cmd: Add `trace-cmd setup-guest` command Slavomir Kaslev (VMware)
2019-06-18 14:44 ` Slavomir Kaslev (VMware) [this message]
2019-06-18 14:44 ` [PATCH v12 11/13] trace-cmd: Add setup-guest flag for attaching FIFOs to the guest VM config Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 12/13] trace-cmd: Add splice() recording from FIFO without additional pipe buffer Slavomir Kaslev (VMware)
2019-06-18 14:44 ` [PATCH v12 13/13] trace-cmd: Add support for tracing VMware Workstation VMs by name Slavomir Kaslev (VMware)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190618144455.3954-11-slavomir.kaslev@gmail.com \
--to=slavomir.kaslev@gmail.com \
--cc=linux-trace-devel@vger.kernel.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).