#include "util.h"
#include "../perf.h"
#include <subcmd/parse-options.h>
#include "evsel.h"
#include "cgroup.h"
#include "evlist.h"

int nr_cgroups;

static int
cgroupfs_find_mountpoint(char *buf, size_t maxlen)
{
	FILE *fp;
	char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
	char *token, *saved_ptr = NULL;
	int found = 0;

	fp = fopen("/proc/mounts", "r");
	if (!fp)
		return -1;

	/*
	 * in order to handle split hierarchy, we need to scan /proc/mounts
	 * and inspect every cgroupfs mount point to find one that has
	 * perf_event subsystem
	 */
	while (fscanf(fp, "%*s %"STR(PATH_MAX)"s %"STR(PATH_MAX)"s %"
				STR(PATH_MAX)"s %*d %*d\n",
				mountpoint, type, tokens) == 3) {

		if (!strcmp(type, "cgroup")) {

			token = strtok_r(tokens, ",", &saved_ptr);

			while (token != NULL) {
				if (!strcmp(token, "perf_event")) {
					found = 1;
					break;
				}
				token = strtok_r(NULL, ",", &saved_ptr);
			}
		}
		if (found)
			break;
	}
	fclose(fp);
	if (!found)
		return -1;

	if (strlen(mountpoint) < maxlen) {
		strcpy(buf, mountpoint);
		return 0;
	}
	return -1;
}

static int open_cgroup(char *name)
{
	char path[PATH_MAX + 1];
	char mnt[PATH_MAX + 1];
	int fd;


	if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1))
		return -1;

	snprintf(path, PATH_MAX, "%s/%s", mnt, name);

	fd = open(path, O_RDONLY);
	if (fd == -1)
		fprintf(stderr, "no access to cgroup %s\n", path);

	return fd;
}

static int add_cgroup(struct perf_evlist *evlist, char *str)
{
	struct perf_evsel *counter;
	struct cgroup_sel *cgrp = NULL;
	int n;
	/*
	 * check if cgrp is already defined, if so we reuse it
	 */
	evlist__for_each_entry(evlist, counter) {
		cgrp = counter->cgrp;
		if (!cgrp)
			continue;
		if (!strcmp(cgrp->name, str))
			break;

		cgrp = NULL;
	}

	if (!cgrp) {
		cgrp = zalloc(sizeof(*cgrp));
		if (!cgrp)
			return -1;

		cgrp->name = str;

		cgrp->fd = open_cgroup(str);
		if (cgrp->fd == -1) {
			free(cgrp);
			return -1;
		}
	}

	/*
	 * find corresponding event
	 * if add cgroup N, then need to find event N
	 */
	n = 0;
	evlist__for_each_entry(evlist, counter) {
		if (n == nr_cgroups)
			goto found;
		n++;
	}
	if (atomic_read(&cgrp->refcnt) == 0)
		free(cgrp);

	return -1;
found:
	atomic_inc(&cgrp->refcnt);
	counter->cgrp = cgrp;
	return 0;
}

void close_cgroup(struct cgroup_sel *cgrp)
{
	if (cgrp && atomic_dec_and_test(&cgrp->refcnt)) {
		close(cgrp->fd);
		zfree(&cgrp->name);
		free(cgrp);
	}
}

int parse_cgroups(const struct option *opt __maybe_unused, const char *str,
		  int unset __maybe_unused)
{
	struct perf_evlist *evlist = *(struct perf_evlist **)opt->value;
	const char *p, *e, *eos = str + strlen(str);
	char *s;
	int ret;

	if (list_empty(&evlist->entries)) {
		fprintf(stderr, "must define events before cgroups\n");
		return -1;
	}

	for (;;) {
		p = strchr(str, ',');
		e = p ? p : eos;

		/* allow empty cgroups, i.e., skip */
		if (e - str) {
			/* termination added */
			s = strndup(str, e - str);
			if (!s)
				return -1;
			ret = add_cgroup(evlist, s);
			if (ret) {
				free(s);
				return -1;
			}
		}
		/* nr_cgroups is increased een for empty cgroups */
		nr_cgroups++;
		if (!p)
			break;
		str = p+1;
	}
	return 0;
}
mmit message (<a href='/cgit.cgi/linux/net-next.git/log/include/clocksource/pxa.h?id=42d5aa76ec8fc9602922cc590a437ecd6693523b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
/gpio/gpio.h?id=f63cf464fc379382a271f94ddef36e8c5a0628eb&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
ption value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;</td><td class='right'>2017-01-30 19:27:10 -0500</td></tr>
<tr><th>committer</th><td>Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;</td><td class='right'>2017-01-31 09:13:49 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/irda/irlmp_event.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>79c6f448c8b79c321e4a1f31f98194e4f6b6cae7</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/irda/irlmp_event.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>370efda701f03cccf21e02bb1fdd3b852547d75c</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/irda/irlmp_event.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>net/irda/irlmp_event.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/irda/irlmp_event.c?id=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>0c744ea4f77d72b3dcebb7a8f2684633ec79be88</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/irda/irlmp_event.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7&amp;id2=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>diff</a>)</td></tr></table>
<div class='commit-subject'>tracing: Fix hwlat kthread migration</div><div class='commit-msg'>The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.

The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.

Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>Diffstat</a> (limited to 'net/irda/irlmp_event.c')</div><table summary='diffstat' class='diffstat'>