commit 788314fcd19a0728b05839a35c5b9fd6e9c57f8d
parent 742d6606c16b27283c5942e3df326a57571783e9
Author: Jesus Galan Lopez (yiyus) <yiyu.jgl@gmail.com>
Date: Sat, 26 Jun 2010 10:55:34 +0200
cpulimit working in linux
Diffstat:
4 files changed, 169 insertions(+), 0 deletions(-)
diff --git a/src/9vx/Makefrag b/src/9vx/Makefrag
@@ -32,6 +32,7 @@ all: 9vx/9vx
PLAN9_OBJS = \
$(addprefix 9vx/, \
bootcode.o \
+ cpulimit-$(OS).o \
conf.o \
devaudio.o \
devaudio-$(PLAN9AUDIO).o \
diff --git a/src/9vx/cpulimit-linux.c b/src/9vx/cpulimit-linux.c
@@ -0,0 +1,160 @@
+/*
+ * plimit-linux.c - Process limiting support for Linux systems.
+ *
+ * Copyright (c) 2008 by Devon H. O'Dell <devon.odell@gmail.com>
+ * Copyright (c) 2010 by Devon H. O'Dell <devon.odell@gmail.com>
+ *
+ * This software is released under a 2-clause BSD license.
+ */
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/mman.h>
+
+#include <fcntl.h>
+#include <limits.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "u.h"
+
+#define timediff(x, y) \
+ (((x)->tv_sec - (y)->tv_sec) * 1000000 + \
+ ((x)->tv_usec - (y)->tv_usec))
+
+int pid;
+
+void
+limit(int percent) {
+ struct timespec sleep_slice;
+ struct timespec work_slice;
+ struct timeval last_sample;
+ struct timeval last_start;
+ struct timeval last_end;
+ double last_usage;
+ int last_pstart;
+ double lim;
+ double rat;
+ double cpu;
+ char buf[1024];
+ char stat[MAXPATHLEN];
+ long hz;
+ int c;
+
+ hz = sysconf(_SC_CLK_TCK);
+
+ lim = (double)percent / 100;
+ rat = cpu = -1;
+ last_usage = 0.0;
+ c = last_pstart = -1;
+
+ snprintf(stat, MAXPATHLEN, "/proc/%d/stat", pid);
+
+ memset(&sleep_slice, 0, sizeof(struct timespec));
+ memset(&work_slice, 0, sizeof(struct timespec));
+ memset(&last_sample, 0, sizeof(struct timeval));
+ memset(&last_start, 0, sizeof(struct timeval));
+ memset(&last_end, 0, sizeof(struct timeval));
+
+ while (1) {
+ struct timeval now;
+ int seen_paren;
+ char *tmp;
+ long uj;
+ long sj;
+ long dt;
+ int n;
+ int r;
+ long t;
+
+ t = open(stat, O_RDONLY);
+ if (t < 0)
+ exit(1);
+ tmp = buf;
+ while ((n = read(t, tmp, 1024)) != 0)
+ tmp += n;
+ close(t);
+
+ seen_paren = n = 0;
+ while (buf[n] != ' ' && seen_paren == 0) {
+ if (buf[n] == ')')
+ seen_paren = 1;
+ n++;
+ }
+
+ r = 0;
+ while (r < 13)
+ if (buf[n++] == ' ')
+ r++;
+
+ uj = strtol(&buf[n], &tmp, 10);
+ sj = strtol(tmp, NULL, 10);
+
+ t = (uj + sj) * hz;
+
+ gettimeofday(&now, NULL);
+ if (last_pstart < 0) {
+ last_sample = now;
+ last_pstart = t;
+
+ kill(pid, SIGSTOP);
+ continue;
+ }
+
+ dt = timediff(&now, &last_sample);
+
+ if (last_usage == 0.0)
+ last_usage = ((t - last_pstart) / (dt * hz / 1000000.0));
+ else
+ last_usage = 0.96 * last_usage + 0.96 * ((t - last_pstart) / (dt * hz / 1000000.0));
+
+ last_sample = now;
+ last_pstart = t;
+
+ if (cpu < 0) {
+ cpu = lim;
+ rat = cpu;
+ work_slice.tv_nsec = 100000000 * lim;
+ } else {
+ rat = MIN(rat / cpu * lim, 1);
+ work_slice.tv_nsec = 100000000 * rat;
+ }
+
+ sleep_slice.tv_nsec = 100000000 - work_slice.tv_nsec;
+
+ kill(pid, SIGCONT);
+
+ gettimeofday(&last_start, NULL);
+ nanosleep(&work_slice, NULL);
+ gettimeofday(&last_end, NULL);
+
+ if (sleep_slice.tv_nsec > 0) {
+ kill(pid, SIGSTOP);
+ nanosleep(&sleep_slice, NULL);
+ }
+ }
+}
+
+void
+quit(int sig){
+ kill(pid, SIGCONT);
+ exit(0);
+}
+
+void
+plimit(pid_t p, int lim)
+{
+ if(fork() > 0)
+ return;
+
+ signal(SIGINT, quit);
+ signal(SIGTERM, quit);
+
+ pid = p;
+ limit(lim);
+}
diff --git a/src/9vx/main.c b/src/9vx/main.c
@@ -212,6 +212,13 @@ main(int argc, char **argv)
#endif
/*
+ * After fork to deal with the correct pid.
+ * The cpu limiter will run in a new process.
+ */
+ if(cpulimit != 0)
+ plimit(getpid(), cpulimit);
+
+ /*
* Have to do this after fork; on OS X child does
* not inherit sigaltstack.
*/
diff --git a/src/9vx/unix.h b/src/9vx/unix.h
@@ -63,3 +63,4 @@ typedef long long int64;
#define USED(x) ((void)(x))
+void plimit(pid_t, int);
