linux-kernel - Does sysrq break something?

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Date:	Mon, 12 May 2008 21:16:30 +0900
From:	Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
To:	linux-kernel@...r.kernel.org
Subject: Does sysrq break something?

Hello.

I'm trying to get a sysrq dump when the system hangs.
But unfortunately, typing sysrq key from the keyboard
doesn't work after the system hangs.
So, I'm trying to get a sysrq dump by automatically
writing to /proc/sysrq-trigger using a program.

  #include <stdio.h>
  #include <unistd.h>

  int main(int argc, char *argv[]) {
  	FILE *fp = fopen("/proc/sys/kernel/sysrq", "w");
  	if (!fp) return 1;
  	fprintf(fp, "1\n");
  	fclose(fp);
  	fp = fopen("/proc/sysrq-trigger", "w");
  	if (!fp) return 1;
  	while (1) {
  		sleep(60);
  		fprintf(fp, "t\n");
  		fflush(fp);
  	}
  	return 0;
  }

Is running this program safe?

In other words, does invoking sysrq routine break or taint something?

Regards.
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