Author: cem Date: Sat Oct 20 18:42:28 2018 New Revision: 339471 URL: https://svnweb.freebsd.org/changeset/base/339471
Log: tty info (^T): Add optional kernel stack(9) traces It is often useful for developers and administrators to determine a running thread's stack for debugging purposes. With this feature, using ^T will print that information For now, the feature is disabled by default. Enable with sysctl kern.tty_info_kstacks=1. Discussed with: markj Reviewed by: oshogbo Relnotes: yes Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D17621 Modified: head/sys/kern/tty_info.c Modified: head/sys/kern/tty_info.c ============================================================================== --- head/sys/kern/tty_info.c Sat Oct 20 18:37:21 2018 (r339470) +++ head/sys/kern/tty_info.c Sat Oct 20 18:42:28 2018 (r339471) @@ -49,11 +49,14 @@ __FBSDID("$FreeBSD$"); #include <sys/cons.h> #include <sys/kdb.h> #include <sys/lock.h> +#include <sys/malloc.h> #include <sys/mutex.h> #include <sys/proc.h> #include <sys/resourcevar.h> #include <sys/sbuf.h> #include <sys/sched.h> +#include <sys/stack.h> +#include <sys/sysctl.h> #include <sys/systm.h> #include <sys/tty.h> @@ -233,6 +236,11 @@ sbuf_tty_drain(void *a, const char *d, int len) return (-ENXIO); } +static bool tty_info_kstacks = false; +SYSCTL_BOOL(_kern, OID_AUTO, tty_info_kstacks, CTLFLAG_RWTUN, + &tty_info_kstacks, 0, + "Enable printing kernel stack(9) traces on ^T (tty info)"); + /* * Report on state of foreground process group. */ @@ -240,12 +248,13 @@ void tty_info(struct tty *tp) { struct timeval rtime, utime, stime; + struct stack stack; struct proc *p, *ppick; struct thread *td, *tdpick; const char *stateprefix, *state; struct sbuf sb; long rss; - int load, pctcpu; + int load, pctcpu, sterr; pid_t pid; char comm[MAXCOMLEN + 1]; struct rusage ru; @@ -320,6 +329,15 @@ tty_info(struct tty *tp) else state = "unknown"; pctcpu = (sched_pctcpu(td) * 10000 + FSCALE / 2) >> FSHIFT; + if (tty_info_kstacks) { + stack_zero(&stack); + if (TD_IS_SWAPPED(td) || TD_IS_RUNNING(td)) + sterr = stack_save_td_running(&stack, td); + else { + stack_save_td(&stack, td); + sterr = 0; + } + } thread_unlock(td); if (p->p_state == PRS_NEW || p->p_state == PRS_ZOMBIE) rss = 0; @@ -340,6 +358,9 @@ tty_info(struct tty *tp) (long)utime.tv_sec, utime.tv_usec / 10000, (long)stime.tv_sec, stime.tv_usec / 10000, pctcpu / 100, rss); + + if (tty_info_kstacks && sterr == 0) + stack_sbuf_print_flags(&sb, &stack, M_NOWAIT); out: sbuf_finish(&sb); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
