most one call to pmap_qremove(), and thus one TLB shootdown, instead of one
call and TLB shootdown per page.
Simplify the interface to vm_hold_free_pages().
MFC after: 3 weeks
was needed at preliminary version of the patch, where number of CPU ticks
was divided strictly on 16 seconds. Final code instead uses real interval
duration, so precise interval should not be important. Same time aliasing
issues around second boundary causes false positives, periodically logging
useless "t_delta ... too long/short" messages when HZ set below 256.
the maintenance of vm_pageout_deficit can be localized to just two places:
vm_page_alloc() and vm_pageout_scan().
This change also corrects an off-by-one error in the maintenance of
vm_pageout_deficit. Historically, the buffer cache functions, allocbuf()
and vm_hold_load_pages(), have not taken into account that vm_page_alloc()
already increments vm_pageout_deficit by one.
Reviewed by: kib
- Fix a bug where thread may be in sleeping state but the wchan won't
be set, leading to an empty container for sleepq_type(). [0]
Sponsored by: Sandvine Incorporated
[0] Submitted by: Bryan Venteicher
<bryanv at daemoninthecloset dot org>
MFC after: 3 days
X-MFC: 209577
There are special cases where tty_rel_free() can be called twice in a
row, namely when closing and revoking the TTY at the same moment. Only
call destroy_dev_sched_cb() once.
Reported by: Jeremie Le Hen
MFC after: 1 week
specify the increment of vm_pageout_deficit when sleeping due to page
shortage. Then, in allocbuf(), the code to allocate pages when extending
vmio buffer can be replaced by a call to vm_page_grab().
Suggested and reviewed by: alc
MFC after: 2 weeks
numbers. This change adds a new function alloc_unr_specific() which
returns the requested unit number if it is free. If the number is
already allocated or out of the range, -1 is returned.
Update alloc_unr(9) manual page accordingly and add a MLINK for
alloc_unr_specific(9).
Discussed on: freebsd-hackers
one or more mappings to the bogus page must be replaced, call pmap_qenter()
just once. Previously, pmap_qenter() was called for each mapping to the
bogus page.
MFC after: 3 weeks
- Rename tdsignal() to tdsendsignal() and make it private to kern_sig.c.
- Add tdsignal() and tdksignal() routines that mirror psignal() and
pksignal() except that they accept a thread as an argument instead of
a process. They send a signal to a specific thread rather than to an
individual process.
Reviewed by: kib
shm syscalls, and initial check for the number of allocated segments
in the module deinitialization code, the following might happen:
after the check for active segment, while waiting for threads to
leave some other syscall, shmget(2) is called. Then, we can end
up with the shared segment that cannot be detached since sysvshm
module is unloaded.
Prevent the leak by rechecking and disclaiming a reference to the vm
object owned by sysvshm module, that might have grown during the drain.
Tested by: pho
Reviewed by: jhb
MFC after: 1 month
syscalls. On the dynamic syscall deregistration, wait until all
threads leave the syscall code. This somewhat increases the safety
of the loadable modules unloading.
Reviewed by: jhb
Tested by: pho
MFC after: 1 month
not providing a destination address and using ktrace.
* Do not copy out kernel memory when providing sinfo for sctp_recvmsg().
Both bug where reported by Valentin Nechayev.
The first bug results in a kernel panic.
MFC after: 3 days.
believed that all 486-class CPUs FreeBSD is capable to run on, either
have no FPU and cannot use external coprocessor, or have FPU on the
package and can use #MF.
Reviewed by: bde
Tested by: pho (previous version)
writing event timer drivers, for choosing best possible drivers by machine
independent code and for operating them to supply kernel with hardclock(),
statclock() and profclock() events in unified fashion on various hardware.
Infrastructure provides support for both per-CPU (independent for every CPU
core) and global timers in periodic and one-shot modes. MI management code
at this moment uses only periodic mode, but one-shot mode use planned for
later, as part of tickless kernel project.
For this moment infrastructure used on i386 and amd64 architectures. Other
archs are welcome to follow, while their current operation should not be
affected.
This patch updates existing drivers (i8254, RTC and LAPIC) for the new
order, and adds event timers support into the HPET driver. These drivers
have different capabilities:
LAPIC - per-CPU timer, supports periodic and one-shot operation, may
freeze in C3 state, calibrated on first use, so may be not exactly precise.
HPET - depending on hardware can work as per-CPU or global, supports
periodic and one-shot operation, usually provides several event timers.
i8254 - global, limited to periodic mode, because same hardware used also
as time counter.
RTC - global, supports only periodic mode, set of frequencies in Hz
limited by powers of 2.
Depending on hardware capabilities, drivers preferred in following orders,
either LAPIC, HPETs, i8254, RTC or HPETs, LAPIC, i8254, RTC.
User may explicitly specify wanted timers via loader tunables or sysctls:
kern.eventtimer.timer1 and kern.eventtimer.timer2.
If requested driver is unavailable or unoperational, system will try to
replace it. If no more timers available or "NONE" specified for second,
system will operate using only one timer, multiplying it's frequency by few
times and uing respective dividers to honor hz, stathz and profhz values,
set during initial setup.
New code that creates character devices shouldn't use device unit
numbers, but only si_drv[12] to hold pointer to per-device data. Make
this function more future proof by removing the unit number argument.
Discussed with: kib
- Allow setting format, resolution and accuracy of BPF time stamps per
listener. Previously, we were only able to use microtime(9). Now we can
set various resolutions and accuracies with ioctl(2) BIOCSTSTAMP command.
Similarly, we can get the current resolution and accuracy with BIOCGTSTAMP
command. Document all supported options in bpf(4) and their uses.
- Introduce new time stamp 'struct bpf_ts' and header 'struct bpf_xhdr'.
The new time stamp has both 64-bit second and fractional parts. bpf_xhdr
has this time stamp instead of 'struct timeval' for bh_tstamp. The new
structures let us use bh_tstamp of same size on both 32-bit and 64-bit
platforms without adding additional shims for 32-bit binaries. On 64-bit
platforms, size of BPF header does not change compared to bpf_hdr as its
members are already all 64-bit long. On 32-bit platforms, the size may
increase by 8 bytes. For backward compatibility, struct bpf_hdr with
struct timeval is still the default header unless new time stamp format is
explicitly requested. However, the behaviour may change in the future and
all relevant code is wrapped around "#ifdef BURN_BRIDGES" for now.
- Add experimental support for tagging mbufs with time stamps from a lower
layer, e.g., device driver. Currently, mbuf_tags(9) is used to tag mbufs.
The time stamps must be uptime in 'struct bintime' format as binuptime(9)
and getbinuptime(9) do.
Reviewed by: net@
flags to specify M_WAITOK/M_NOWAIT. M_WAITOK allows devctl to sleep for
the memory allocation.
As Warner noted, allowing the functions to sleep might cause
reordering of the queued notifications.
Reviewed by: imp, jh
MFC after: 3 weeks
