Rework how we store process times in the kernel such that we always store
the raw values including for child process statistics and only compute the
system and user timevals on demand.

- Fix the var

Rework how we store process times in the kernel such that we always store
the raw values including for child process statistics and only compute the
system and user timevals on demand.

- Fix the various kern_wait() syscall wrappers to only pass in a rusage
pointer if they are going to use the result.
- Add a kern_getrusage() function for the ABI syscalls to use so that they
don't have to play stackgap games to call getrusage().
- Fix the svr4_sys_times() syscall to just call calcru() to calculate the
times it needs rather than calling getrusage() twice with associated
stackgap, etc.
- Add a new rusage_ext structure to store raw time stats such as tick counts
for user, system, and interrupt time as well as a bintime of the total
runtime. A new p_rux field in struct proc replaces the same inline fields
from struct proc (i.e. p_[isu]ticks, p_[isu]u, and p_runtime). A new p_crux
field in struct proc contains the "raw" child time usage statistics.
ruadd() has been changed to handle adding the associated rusage_ext
structures as well as the values in rusage. Effectively, the values in
rusage_ext replace the ru_utime and ru_stime values in struct rusage. These
two fields in struct rusage are no longer used in the kernel.
- calcru() has been split into a static worker function calcru1() that
calculates appropriate timevals for user and system time as well as updating
the rux_[isu]u fields of a passed in rusage_ext structure. calcru() uses a
copy of the process' p_rux structure to compute the timevals after updating
the runtime appropriately if any of the threads in that process are
currently executing. It also now only locks sched_lock internally while
doing the rux_runtime fixup. calcru() now only requires the caller to
hold the proc lock and calcru1() only requires the proc lock internally.
calcru() also no longer allows callers to ask for an interrupt timeval
since none of them actually did.
- calcru() now correctly handles threads executing on other CPUs.
- A new calccru() function computes the child system and user timevals by
calling calcru1() on p_crux. Note that this means that any code that wants
child times must now call this function rather than reading from p_cru
directly. This function also requires the proc lock.
- This finishes the locking for rusage and friends so some of the Giant locks
in exit1() and kern_wait() are now gone.
- The locking in ttyinfo() has been tweaked so that a shared lock of the
proctree lock is used to protect the process group rather than the process
group lock. By holding this lock until the end of the function we now
ensure that the process/thread that we pick to dump info about will no
longer vanish while we are trying to output its info to the console.

Submitted by: bde (mostly)
MFC after: 1 month

show more ...

Update previous commit to:
* Obtain/release schedlock around calls to calcru.
* Sort switch cases which do not cascade per style(9).
* Sort local variables per style(9).
* Remove "superfluous

Update previous commit to:
* Obtain/release schedlock around calls to calcru.
* Sort switch cases which do not cascade per style(9).
* Sort local variables per style(9).
* Remove "superfluous" whitespace.
* Cleanup handling of NULL uap->tp in clock_getres(). It would probably
be better to return EFAULT like clock_gettime() does by passing the
pointer to copyout(), but I presume it was written to not fail on
purpose in the original code. I'll defer to -standards on this one.

Reported by: bde

show more ...

Implement CLOCK_VIRTUAL and CLOCK_PROF for clock_gettime(2) and
clock_getres(2).

Reviewed by: phk
PR: 23304

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core

constify the second args to timevaladd() and timevalsub().

Use __FBSDID().

Wait for the real interval timer callout handler to finish executing if it
is currently executing when we try to remove it in exit1(). Without this,
it was possible for the callout to bogusly rearm

Wait for the real interval timer callout handler to finish executing if it
is currently executing when we try to remove it in exit1(). Without this,
it was possible for the callout to bogusly rearm itself and eventually
refire after the process had been free'd resulting in a panic.

PR: kern/51964
Reported by: Jilles Tjoelker <jilles@stack.nl>
Reviewed by: tegge, bde

show more ...

In setitimer(2), if the it_value of the new itimer value is clear, then
don't add the current time to it, but leave it as clear so that when the
timer is disabled, the it_value is always clear.

Revi

In setitimer(2), if the it_value of the new itimer value is clear, then
don't add the current time to it, but leave it as clear so that when the
timer is disabled, the it_value is always clear.

Reviewed by: bde
Approved by: re (rwatson)

show more ...

o fix ppsratecheck to interpret a maxpps of zero as "ignore everything"
o add a comment explaining the significance of using 0 or -1 (actually
any negative value) for maxpps

OK, I was too sleepy there...

Pointy hat over here!

Implement CLOCK_MONOTONIC.

Remove duplicate includes.

Submitted by: Cyril Nguyen-Huu <cyril@ci0.org>

Use the proc lock to protect p_realtimer instead of Giant, and obtain
sched_lock around accesses to p_stats->p_timer[] to avoid a potential
race with hardclock. getitimer(), setitimer() and the reali

Use the proc lock to protect p_realtimer instead of Giant, and obtain
sched_lock around accesses to p_stats->p_timer[] to avoid a potential
race with hardclock. getitimer(), setitimer() and the realitexpire()
callout are now Giant-free.

show more ...

Split the global timezone structure into two integer fields to
prevent the compiler from optimizing assignments into byte-copy
operations which might make access to the individual fields non-atomic.

Split the global timezone structure into two integer fields to
prevent the compiler from optimizing assignments into byte-copy
operations which might make access to the individual fields non-atomic.

Use the individual fields throughout, and don't bother locking them with
Giant: it is no longer needed.

Inspired by: tjr

show more ...

No need to lock Giant around call to nanosleep1() in nanosleep().

Avoid holding Giant across copyout() in gettimeofday() and getitimer().

Remove unnecessary locking of Giant around nanotime() in clock_gettime().

useracc() is mpsafe so we only need to hold Giant
over the call to nanosleep1()

Pointed out by: tjr

o reduce the overhead of calling ppsratecheck by using ticks instead of
calling getmicrouptime (but maintain the struct timeval-based calling
convention for compatibility)
o eliminate the use of

o reduce the overhead of calling ppsratecheck by using ticks instead of
calling getmicrouptime (but maintain the struct timeval-based calling
convention for compatibility)
o eliminate the use of timersub in ratecheck

Note that flood ping tests indicate ppsratecheck is inaccurate (but on the
conservative side) with this revised implementation. If more accuracy is
needed we'll have to introduce an alternate interface or increase the
overhead.

Reviewed by: silby, dillon, bde

show more ...

add generic rate limiting support from netbsd; ratelimit is purely time based,
ppsratecheck is for controlling packets/second

Obtained from: netbsd

SCARGS removal take II.

Backout removal SCARGS, the code freeze is only "selectively" over.

Remove SCARGS.

Reviewed by: md5

Introduce mac_check_system_settime(), a MAC check allowing policies to
augment the system policy for changing the system time.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associat

Introduce mac_check_system_settime(), a MAC check allowing policies to
augment the system policy for changing the system time.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

show more ...

Round up instead of towards 0 in clock_getres() so that a resolution of
0 is never returned.

PR: 41781
MFC after: 3 days