Re: [PATCH] Adjust 'ps H' to include kthread names by default

On 01/17/2013 15:22, John Baldwin wrote:
> Running 'ps axH' on a current system results in a lot of kthreads with not
> very useful names (unless you add -c):
>
>    PID  TT  STAT      TIME COMMAND
>      0  ??  DLs    1:09.52 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs    0:03.82 [kernel]
>      0  ??  DLs    1:15.14 [kernel]
>      0  ??  DLs    0:00.00 [kernel]
>      0  ??  DLs   39:24.55 [kernel]
>      0  ??  DLs    0:00.04 [kernel]
>
> This patch changes this to:
>
>    PID  TT  STAT      TIME COMMAND
>      0  ??  DLs    1:09.53 [kernel/swapper]
>      0  ??  DLs    0:00.00 [kernel/firmware tas]
>      0  ??  DLs    0:00.00 [kernel/ffs_trim tas]
>      0  ??  DLs    0:00.00 [kernel/acpi_task_0]
>      0  ??  DLs    0:00.00 [kernel/acpi_task_1]
>      0  ??  DLs    0:00.00 [kernel/acpi_task_2]
>      0  ??  DLs    0:00.00 [kernel/aiod_bio tas]
>      0  ??  DLs    0:03.82 [kernel/thread taskq]
>      0  ??  DLs    1:15.19 [kernel/nvidia taskq]
>      0  ??  DLs    0:00.00 [kernel/kqueue taskq]
>      0  ??  DLs   39:26.82 [kernel/em0 taskq]
>      0  ??  DLs    0:00.04 [kernel/mca taskq]
>
> In theory this will affect any process for which an argv can't be fetched, but
> in practice it mostly helps with kthreads.

Yes, please, and thank you.

The patch looks fine to me.

> Index: ps.c
> ===================================================================
> --- ps.c	(revision 245225)
> +++ ps.c	(working copy)
> _at__at_ -141,7 +141,7 _at__at_
>   static void	*expand_list(struct listinfo *);
>   static const char *
>   		 fmt(char **(*)(kvm_t *, const struct kinfo_proc *, int),
> -		    KINFO *, char *, int);
> +		    KINFO *, char *, char *, int);
>   static void	 free_list(struct listinfo *);
>   static void	 init_list(struct listinfo *, addelem_rtn, int, const char *);
>   static char	*kludge_oldps_options(const char *, char *, const char *);
> _at__at_ -1163,11 +1163,12 _at__at_
>   
>   static const char *
>   fmt(char **(*fn)(kvm_t *, const struct kinfo_proc *, int), KINFO *ki,
> -    char *comm, int maxlen)
> +    char *comm, char *thread, int maxlen)
>   {
>   	const char *s;
>   
> -	s = fmt_argv((*fn)(kd, ki->ki_p, termwidth), comm, maxlen);
> +	s = fmt_argv((*fn)(kd, ki->ki_p, termwidth), comm,
> +	    ki->ki_p->ki_numthreads > 1 ? thread : NULL, maxlen);
>   	return (s);
>   }
>   
> _at__at_ -1195,7 +1196,7 _at__at_
>   			ki->ki_args = strdup("<defunct>");
>   		else if (UREADOK(ki) || (ki->ki_p->ki_args != NULL))
>   			ki->ki_args = strdup(fmt(kvm_getargv, ki,
> -			    ki->ki_p->ki_comm, MAXCOMLEN));
> +			    ki->ki_p->ki_comm, ki->ki_p->ki_tdname, MAXCOMLEN));
>   		else
>   			asprintf(&ki->ki_args, "(%s)", ki->ki_p->ki_comm);
>   		if (ki->ki_args == NULL)
> _at__at_ -1206,7 +1207,7 _at__at_
>   	if (needenv) {
>   		if (UREADOK(ki))
>   			ki->ki_env = strdup(fmt(kvm_getenvv, ki,
> -			    (char *)NULL, 0));
> +			    (char *)NULL, (char *)NULL, 0));
>   		else
>   			ki->ki_env = strdup("()");
>   		if (ki->ki_env == NULL)
> Index: fmt.c
> ===================================================================
> --- fmt.c	(revision 245225)
> +++ fmt.c	(working copy)
> _at__at_ -105,7 +105,7 _at__at_
>   }
>   
>   const char *
> -fmt_argv(char **argv, char *cmd, size_t maxlen)
> +fmt_argv(char **argv, char *cmd, char *thread, size_t maxlen)
>   {
>   	size_t len;
>   	char *ap, *cp;
> _at__at_ -122,9 +122,14 _at__at_
>   	cp = malloc(len);
>   	if (cp == NULL)
>   		errx(1, "malloc failed");
> -	if (ap == NULL)
> -		sprintf(cp, "[%.*s]", (int)maxlen, cmd);
> -	else if (strncmp(cmdpart(argv[0]), cmd, maxlen) != 0)
> +	if (ap == NULL) {
> +		if (showthreads && thread != NULL) {
> +			asprintf(&ap, "%s/%s", cmd, thread);
> +			sprintf(cp, "[%.*s]", (int)maxlen, ap);
> +			free(ap);
> +		} else
> +			sprintf(cp, "[%.*s]", (int)maxlen, cmd);
> +	} else if (strncmp(cmdpart(argv[0]), cmd, maxlen) != 0)
>   		sprintf(cp, "%s (%.*s)", ap, (int)maxlen, cmd);
>   	else
>   		strcpy(cp, ap);
> Index: extern.h
> ===================================================================
> --- extern.h	(revision 245225)
> +++ extern.h	(working copy)
> _at__at_ -51,7 +51,7 _at__at_
>   char	 *elapseds(KINFO *, VARENT *);
>   char	 *emulname(KINFO *, VARENT *);
>   VARENT	*find_varentry(VAR *);
> -const	 char *fmt_argv(char **, char *, size_t);
> +const	 char *fmt_argv(char **, char *, char *, size_t);
>   double	 getpcpu(const KINFO *);
>   char	 *kvar(KINFO *, VARENT *);
>   char	 *label(KINFO *, VARENT *);
>
>