are places where the "main thread" of the booting kernel (either the
thread which later becomes swapper or the thread which later becomes
init) has to stop and wait for action to take place in another thread
before continuing.
There are currently three such holds:
1. The intr_config_hooks SYSINIT waits for hooks registered via the
config_intrhook_establish function; this allows (typically) devices
which need interrupts enabled to complete their initialization to do
so before root is mounted.
2. The g_waitidle function waits for the GEOM event queue to be empty;
this ensures that all of the disks which have been attached have been
tasted before we attempt to mount root.
3. The vfs_mountroot_wait function (in addition to calling g_waitidle)
waits for holds registered via root_mount_hold; among other things, this
is used by the USB subsystem to ensure that we don't fail to mount root
if it's located on a USB disk which takes a while to probe.
METHOD and STATICMETHOD declarations; that code will be inserted
into the dispatch function before and after the method call.
Use this functionality and the TSLOG framework to record DEVICE_ATTACH
and DEVICE_PROBE entry/exit timestamps.
independent functions with important roles in the early boot process:
mi_startup (with the "exit" recorded when it becomes swapper),
start_init (with the "exit" recorded when the thread is about to
"return" into the newly created init process), vfs_mountroot, and
vfs_mountroot_wait.
The entry must be logged "manually" using TSRAW rather than TSENTER
since PCPU data structures have not yet been initialized and thus
curthread cannot be accessed; &thread0 is what will become curthread
later in hammer_time.
Other MD initialization code should be similarly instrumented in order
to gain visibility into the time spent before entering mi_startup; this
will require some care and testing from people with access to such
hardware.
These are intended for debugging purposes and should not be added to
"generic" kernel configurations since they result in a nontrivial amount
of memory being set aside for this purpose, can break if kernel modules are
unloaded, and can potentially leak a dangerous amount of information about
timestamps used as a source of kernel entropy.
This is a very primitive system, intended for use in measuring performance
during the early system boot, before more sophisticated tools like DTrace
or infrastructure like kernel memory allocation and mutexes are available.
Because this code records pointers to strings rather than copying strings
(in order to keep the memory usage more manageable), if a kernel module is
unloaded after logging an event, Bad Things can happen. Users are advised
to not do that.
Since cycle counts from the early kernel boot are used as an initial entropy
source, publishing this information to userland could result in inadequate
entropy being kept private to the kernel RNG. Users are advised to not
enable this on systems with untrusted users.
Discussed on: freebsd-current
We use /usr/share/skel instead of /etc/skel. The existence of /etc/skel
has confused people.
PR: 46062 (submitted 2002-12-07)
PR: 218897
Submitted by: carl@slackerbsd.org
Submitted by: asv@inhio.net
instead of hard-coding a default. This information is passed implicitly by
the PS3 firmware and can be relied upon. Also adjust the default mode, if
somehow firmware doesn't pass one, to 1920x1080 from 720x480 since it is
2017.
MFC after: 2 weeks
libfdt will assume a writable fdt overlay blob has been passed in, so make
ours compatible to allow easier review when we try to drop libfdt into
place. overlay from the calling context is writable, making it safe to
simply rip out everything related to copying the overlay blob in
fdt_overlay_apply.
I note here that we still have problems: fdt_overlay_apply, both our version
and libfdt's, may fail and have already clobbered the base fdt to some
extent. Future work will make sure we don't apply a potentially bogus fdt,
instead discarding the base fdt if we had an error.
Reviewed by: gonzo
Differential Revision: https://reviews.freebsd.org/D13695
swp_pager_meta_ctl(), with no opportunity to recognize freeing of
consecutive blocks and free fewer block ranges. To open that opportunity,
this change removes the SWM_FREE option from swp_pager_meta_ctl(), and
compels the caller to do the freeing when a valid block address is returned.
In swap_pager_copy(), these frees are aggregated, so that a sequence of them
can be done at one time.
The only other caller to swp_pager_meta_ctl() that passed SWM_FREE,
swp_pager_unswapped(), is also modified to handle its single free
explicitly.
Submitted by: Doug Moore <dougm@rice.edu>
Reviewed by: kib (an earlier version)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13290
Both files originated in NetBSD:
sysv_ipc.c CVS 1.9:
Most of their changes don't apply to us as we already have similar
changes. This is a better reference for future merges.
sysv_shm.c CVS 1.39:
Most of their changes don't apply to our code but interestingly this
revision merged our changes and is a better point for reference.
Move the VCS tags to the position recommended in our committers guide
(section 8),
No functional change.
In both rw and sx locks we always go to sleep if the lock owner is not
running.
We do spin for some time if the lock is read-locked.
However, if we decide to go to sleep due to the lock owner being off cpu
and after sleepq/turnstile gets acquired the lock is read-locked, we should
fallback to the aforementioned wait.
Since this function is effectively slow path, if we get here the lock is most
likely already taken in which case it is cheaper to not blindly attempt the
atomic op.
While here move hwpmc probe out of the loop to match other primitives.
Fully subclass the dwmmc driver and split every driver into multiple files.
There is still a few quirks in the dwmmc driver that will need some work.
Tested On: Pine64 Rock64
Differential Revision: https://reviews.freebsd.org/D13615
The ep(4) driver is the only consumer of the two functions from
elink.c. I removed the standalone module as well, and most likely,
the module metadata is not needed anywhere, but this is for later
cleanup.
Discussed with: imp, jhb
Sponsored by: The FreeBSD Foundation
The i386 FPU (AKA npx) code does not depend on ISA devices at all,
after the support for IRQ13 FPU exceptions was removed. Put the file
into the expected place in the kernel source tree.
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
strnlen is not used at the moment, but it will be when libfdt gets updated.
Prepare for the not-so-distant future by pulling in strnlen.
Noticed because: segfault in ld.bfd due to strnlen missing
libfdt.h should be included before fdt.h, as hinted at by all of libfdt/;
standard include order being libfdt.h, libfdt_env.h, fdt.h.
The current include order also causes problems when libfdt gets updated, as
fdt.h requires some definitions from libfdt.h.
Differential Revision: https://reviews.freebsd.org/D13688
