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-rw-r--r--Documentation/prctl/disable-tsc-on-off-stress-test.c95
1 files changed, 0 insertions, 95 deletions
diff --git a/Documentation/prctl/disable-tsc-on-off-stress-test.c b/Documentation/prctl/disable-tsc-on-off-stress-test.c
deleted file mode 100644
index 1fcd9144..0000000
--- a/Documentation/prctl/disable-tsc-on-off-stress-test.c
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Tests for prctl(PR_GET_TSC, ...) / prctl(PR_SET_TSC, ...)
- *
- * Tests if the control register is updated correctly
- * when set with prctl()
- *
- * Warning: this test will cause a very high load for a few seconds
- *
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <signal.h>
-#include <inttypes.h>
-#include <wait.h>
-
-
-#include <sys/prctl.h>
-#include <linux/prctl.h>
-
-/* Get/set the process' ability to use the timestamp counter instruction */
-#ifndef PR_GET_TSC
-#define PR_GET_TSC 25
-#define PR_SET_TSC 26
-# define PR_TSC_ENABLE 1 /* allow the use of the timestamp counter */
-# define PR_TSC_SIGSEGV 2 /* throw a SIGSEGV instead of reading the TSC */
-#endif
-
-/* snippet from wikipedia :-) */
-
-uint64_t rdtsc() {
-uint32_t lo, hi;
-/* We cannot use "=A", since this would use %rax on x86_64 */
-__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
-return (uint64_t)hi << 32 | lo;
-}
-
-int should_segv = 0;
-
-void sigsegv_cb(int sig)
-{
- if (!should_segv)
- {
- fprintf(stderr, "FATAL ERROR, rdtsc() failed while enabled\n");
- exit(0);
- }
- if (prctl(PR_SET_TSC, PR_TSC_ENABLE) < 0)
- {
- perror("prctl");
- exit(0);
- }
- should_segv = 0;
-
- rdtsc();
-}
-
-void task(void)
-{
- signal(SIGSEGV, sigsegv_cb);
- alarm(10);
- for(;;)
- {
- rdtsc();
- if (should_segv)
- {
- fprintf(stderr, "FATAL ERROR, rdtsc() succeeded while disabled\n");
- exit(0);
- }
- if (prctl(PR_SET_TSC, PR_TSC_SIGSEGV) < 0)
- {
- perror("prctl");
- exit(0);
- }
- should_segv = 1;
- }
-}
-
-
-int main(int argc, char **argv)
-{
- int n_tasks = 100, i;
-
- fprintf(stderr, "[No further output means we're allright]\n");
-
- for (i=0; i<n_tasks; i++)
- if (fork() == 0)
- task();
-
- for (i=0; i<n_tasks; i++)
- wait(NULL);
-
- exit(0);
-}
-