freebsd-dev/sys/kern/tty_info.c

314 lines
8.1 KiB
C
Raw Normal View History

/*-
* Copyright (c) 1982, 1986, 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Copyright (c) 2002 Networks Associates Technologies, Inc.
* All rights reserved.
*
* Portions of this software were developed for the FreeBSD Project by
* ThinkSec AS and NAI Labs, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
/*
* Returns 1 if p2 is "better" than p1
*
* The algorithm for picking the "interesting" process is thus:
*
* 1) Only foreground processes are eligible - implied.
* 2) Runnable processes are favored over anything else. The runner
* with the highest cpu utilization is picked (p_estcpu). Ties are
* broken by picking the highest pid.
* 3) The sleeper with the shortest sleep time is next. With ties,
* we pick out just "short-term" sleepers (P_SINTR == 0).
* 4) Further ties are broken by picking the highest pid.
*/
#define TESTAB(a, b) ((a)<<1 | (b))
#define ONLYA 2
#define ONLYB 1
#define BOTH 3
static int
proc_sum(struct proc *p, fixpt_t *estcpup)
{
struct thread *td;
int estcpu;
int val;
val = 0;
estcpu = 0;
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
if (TD_ON_RUNQ(td) ||
TD_IS_RUNNING(td))
val = 1;
estcpu += sched_pctcpu(td);
thread_unlock(td);
}
*estcpup = estcpu;
return (val);
}
static int
thread_compare(struct thread *td, struct thread *td2)
{
int runa, runb;
int slpa, slpb;
fixpt_t esta, estb;
if (td == NULL)
return (1);
/*
* Fetch running stats, pctcpu usage, and interruptable flag.
*/
thread_lock(td);
runa = TD_IS_RUNNING(td) | TD_ON_RUNQ(td);
slpa = td->td_flags & TDF_SINTR;
esta = sched_pctcpu(td);
thread_unlock(td);
thread_lock(td2);
runb = TD_IS_RUNNING(td2) | TD_ON_RUNQ(td2);
estb = sched_pctcpu(td2);
slpb = td2->td_flags & TDF_SINTR;
thread_unlock(td2);
/*
* see if at least one of them is runnable
*/
switch (TESTAB(runa, runb)) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
break;
}
/*
* favor one with highest recent cpu utilization
*/
if (estb > esta)
return (1);
if (esta > estb)
return (0);
/*
* favor one sleeping in a non-interruptible sleep
*/
switch (TESTAB(slpa, slpb)) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
break;
}
return (td < td2);
}
static int
proc_compare(struct proc *p1, struct proc *p2)
{
int runa, runb;
fixpt_t esta, estb;
if (p1 == NULL)
return (1);
/*
* Fetch various stats about these processes. After we drop the
* lock the information could be stale but the race is unimportant.
*/
PROC_LOCK(p1);
runa = proc_sum(p1, &esta);
PROC_UNLOCK(p1);
PROC_LOCK(p2);
runb = proc_sum(p2, &estb);
PROC_UNLOCK(p2);
/*
* see if at least one of them is runnable
*/
switch (TESTAB(runa, runb)) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
break;
}
/*
* favor one with highest recent cpu utilization
*/
if (estb > esta)
return (1);
if (esta > estb)
return (0);
/*
* weed out zombies
*/
switch (TESTAB(p1->p_state == PRS_ZOMBIE, p2->p_state == PRS_ZOMBIE)) {
case ONLYA:
return (1);
case ONLYB:
return (0);
case BOTH:
break;
}
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
/*
* Report on state of foreground process group.
*/
void
Integrate the new MPSAFE TTY layer to the FreeBSD operating system. The last half year I've been working on a replacement TTY layer for the FreeBSD kernel. The new TTY layer was designed to improve the following: - Improved driver model: The old TTY layer has a driver model that is not abstract enough to make it friendly to use. A good example is the output path, where the device drivers directly access the output buffers. This means that an in-kernel PPP implementation must always convert network buffers into TTY buffers. If a PPP implementation would be built on top of the new TTY layer (still needs a hooks layer, though), it would allow the PPP implementation to directly hand the data to the TTY driver. - Improved hotplugging: With the old TTY layer, it isn't entirely safe to destroy TTY's from the system. This implementation has a two-step destructing design, where the driver first abandons the TTY. After all threads have left the TTY, the TTY layer calls a routine in the driver, which can be used to free resources (unit numbers, etc). The pts(4) driver also implements this feature, which means posix_openpt() will now return PTY's that are created on the fly. - Improved performance: One of the major improvements is the per-TTY mutex, which is expected to improve scalability when compared to the old Giant locking. Another change is the unbuffered copying to userspace, which is both used on TTY device nodes and PTY masters. Upgrading should be quite straightforward. Unlike previous versions, existing kernel configuration files do not need to be changed, except when they reference device drivers that are listed in UPDATING. Obtained from: //depot/projects/mpsafetty/... Approved by: philip (ex-mentor) Discussed: on the lists, at BSDCan, at the DevSummit Sponsored by: Snow B.V., the Netherlands dcons(4) fixed by: kan
2008-08-20 08:31:58 +00:00
tty_info(struct tty *tp)
{
struct timeval rtime, utime, stime;
struct proc *p, *ppick;
struct thread *td, *tdpick;
const char *stateprefix, *state;
long rss;
int load, pctcpu;
pid_t pid;
char comm[MAXCOMLEN + 1];
struct rusage ru;
Integrate the new MPSAFE TTY layer to the FreeBSD operating system. The last half year I've been working on a replacement TTY layer for the FreeBSD kernel. The new TTY layer was designed to improve the following: - Improved driver model: The old TTY layer has a driver model that is not abstract enough to make it friendly to use. A good example is the output path, where the device drivers directly access the output buffers. This means that an in-kernel PPP implementation must always convert network buffers into TTY buffers. If a PPP implementation would be built on top of the new TTY layer (still needs a hooks layer, though), it would allow the PPP implementation to directly hand the data to the TTY driver. - Improved hotplugging: With the old TTY layer, it isn't entirely safe to destroy TTY's from the system. This implementation has a two-step destructing design, where the driver first abandons the TTY. After all threads have left the TTY, the TTY layer calls a routine in the driver, which can be used to free resources (unit numbers, etc). The pts(4) driver also implements this feature, which means posix_openpt() will now return PTY's that are created on the fly. - Improved performance: One of the major improvements is the per-TTY mutex, which is expected to improve scalability when compared to the old Giant locking. Another change is the unbuffered copying to userspace, which is both used on TTY device nodes and PTY masters. Upgrading should be quite straightforward. Unlike previous versions, existing kernel configuration files do not need to be changed, except when they reference device drivers that are listed in UPDATING. Obtained from: //depot/projects/mpsafetty/... Approved by: philip (ex-mentor) Discussed: on the lists, at BSDCan, at the DevSummit Sponsored by: Snow B.V., the Netherlands dcons(4) fixed by: kan
2008-08-20 08:31:58 +00:00
tty_lock_assert(tp, MA_OWNED);
if (tty_checkoutq(tp) == 0)
return;
/* Print load average. */
load = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
ttyprintf(tp, "%sload: %d.%02d ", tp->t_column == 0 ? "" : "\n",
load / 100, load % 100);
if (tp->t_session == NULL) {
ttyprintf(tp, "not a controlling terminal\n");
return;
}
if (tp->t_pgrp == NULL) {
ttyprintf(tp, "no foreground process group\n");
return;
}
PGRP_LOCK(tp->t_pgrp);
if (LIST_EMPTY(&tp->t_pgrp->pg_members)) {
PGRP_UNLOCK(tp->t_pgrp);
ttyprintf(tp, "empty foreground process group\n");
return;
}
/*
* Pick the most interesting process and copy some of its
* state for printing later. This operation could rely on stale
* data as we can't hold the proc slock or thread locks over the
* whole list. However, we're guaranteed not to reference an exited
* thread or proc since we hold the tty locked.
*/
p = NULL;
LIST_FOREACH(ppick, &tp->t_pgrp->pg_members, p_pglist)
if (proc_compare(p, ppick))
p = ppick;
PROC_LOCK(p);
PGRP_UNLOCK(tp->t_pgrp);
td = NULL;
FOREACH_THREAD_IN_PROC(p, tdpick)
if (thread_compare(td, tdpick))
td = tdpick;
stateprefix = "";
thread_lock(td);
if (TD_IS_RUNNING(td))
state = "running";
else if (TD_ON_RUNQ(td) || TD_CAN_RUN(td))
state = "runnable";
else if (TD_IS_SLEEPING(td)) {
/* XXX: If we're sleeping, are we ever not in a queue? */
if (TD_ON_SLEEPQ(td))
state = td->td_wmesg;
else
state = "sleeping without queue";
} else if (TD_ON_LOCK(td)) {
state = td->td_lockname;
stateprefix = "*";
} else if (TD_IS_SUSPENDED(td))
state = "suspended";
else if (TD_AWAITING_INTR(td))
state = "intrwait";
else if (p->p_state == PRS_ZOMBIE)
state = "zombie";
else
state = "unknown";
pctcpu = (sched_pctcpu(td) * 10000 + FSCALE / 2) >> FSHIFT;
thread_unlock(td);
if (p->p_state == PRS_NEW || p->p_state == PRS_ZOMBIE)
rss = 0;
else
rss = pgtok(vmspace_resident_count(p->p_vmspace));
microuptime(&rtime);
timevalsub(&rtime, &p->p_stats->p_start);
rufetchcalc(p, &ru, &utime, &stime);
pid = p->p_pid;
strlcpy(comm, p->p_comm, sizeof comm);
PROC_UNLOCK(p);
/* Print command, pid, state, rtime, utime, stime, %cpu, and rss. */
ttyprintf(tp,
" cmd: %s %d [%s%s] %ld.%02ldr %ld.%02ldu %ld.%02lds %d%% %ldk\n",
comm, pid, stateprefix, state,
(long)rtime.tv_sec, rtime.tv_usec / 10000,
(long)utime.tv_sec, utime.tv_usec / 10000,
(long)stime.tv_sec, stime.tv_usec / 10000,
pctcpu / 100, rss);
}