* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/
-#include <proc/readproc.h>
+#include <dirent.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
return 0;
}
+
+/*
+ * procfs_is_workload_pid - check if a procfs entry contains a comm_prefix* comm
+ *
+ * Check if the procfs entry is a directory of a process, and then check if the
+ * process has a comm with the prefix set in char *comm_prefix. As the
+ * current users of this function only check for kernel threads, there is no
+ * need to check for the threads for the process.
+ *
+ * Return: True if the proc_entry contains a comm file with comm_prefix*.
+ * Otherwise returns false.
+ */
+static int procfs_is_workload_pid(const char *comm_prefix, struct dirent *proc_entry)
+{
+ char buffer[MAX_PATH];
+ int comm_fd, retval;
+ char *t_name;
+
+ if (proc_entry->d_type != DT_DIR)
+ return 0;
+
+ if (*proc_entry->d_name == '.')
+ return 0;
+
+ /* check if the string is a pid */
+ for (t_name = proc_entry->d_name; t_name; t_name++) {
+ if (!isdigit(*t_name))
+ break;
+ }
+
+ if (*t_name != '\0')
+ return 0;
+
+ snprintf(buffer, MAX_PATH, "/proc/%s/comm", proc_entry->d_name);
+ comm_fd = open(buffer, O_RDONLY);
+ if (comm_fd < 0)
+ return 0;
+
+ memset(buffer, 0, MAX_PATH);
+ retval = read(comm_fd, buffer, MAX_PATH);
+
+ close(comm_fd);
+
+ if (retval <= 0)
+ return 0;
+
+ retval = strncmp(comm_prefix, buffer, strlen(comm_prefix));
+ if (retval)
+ return 0;
+
+ /* comm already have \n */
+ debug_msg("Found workload pid:%s comm:%s", proc_entry->d_name, buffer);
+
+ return 1;
+}
+
/*
- * set_comm_sched_attr - set sched params to threads starting with char *comm
+ * set_comm_sched_attr - set sched params to threads starting with char *comm_prefix
*
- * This function uses procps to list the currently running threads and then
- * set the sched_attr *attr to the threads that start with char *comm. It is
+ * This function uses procfs to list the currently running threads and then set the
+ * sched_attr *attr to the threads that start with char *comm_prefix. It is
* mainly used to set the priority to the kernel threads created by the
* tracers.
*/
-int set_comm_sched_attr(const char *comm, struct sched_attr *attr)
+int set_comm_sched_attr(const char *comm_prefix, struct sched_attr *attr)
{
- int flags = PROC_FILLCOM | PROC_FILLSTAT;
- PROCTAB *ptp;
- proc_t task;
+ struct dirent *proc_entry;
+ DIR *procfs;
int retval;
- ptp = openproc(flags);
- if (!ptp) {
- err_msg("error openproc()\n");
- return -ENOENT;
+ if (strlen(comm_prefix) >= MAX_PATH) {
+ err_msg("Command prefix is too long: %d < strlen(%s)\n",
+ MAX_PATH, comm_prefix);
+ return 1;
}
- memset(&task, 0, sizeof(task));
+ procfs = opendir("/proc");
+ if (!procfs) {
+ err_msg("Could not open procfs\n");
+ return 1;
+ }
- while (readproc(ptp, &task)) {
- retval = strncmp(comm, task.cmd, strlen(comm));
- if (retval)
+ while ((proc_entry = readdir(procfs))) {
+
+ retval = procfs_is_workload_pid(comm_prefix, proc_entry);
+ if (!retval)
continue;
- retval = __set_sched_attr(task.tid, attr);
- if (retval)
+
+ /* procfs_is_workload_pid confirmed it is a pid */
+ retval = __set_sched_attr(atoi(proc_entry->d_name), attr);
+ if (retval) {
+ err_msg("Error setting sched attributes for pid:%s\n", proc_entry->d_name);
goto out_err;
- }
+ }
- closeproc(ptp);
+ debug_msg("Set sched attributes for pid:%s\n", proc_entry->d_name);
+ }
return 0;
out_err:
- closeproc(ptp);
+ closedir(procfs);
return 1;
}
projects / platform / kernel / linux-starfive.git / commitdiff