designated initializers. This makes it easier to modify 'struct sysent'
layout.
Reviewed by: kevans
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26530
For a long period value and the duty specified as a percentage,
there could be an overflow.
Using unsigned integers aligns the code with struct pwm_state and allows
to safely use periods up to 4 seconds where supported by drivers.
MFC after: 2 weeks
The hardware supports periods as long as 196 seconds[*] when using the
maximal prescaling of 72000 and maximum cycle count of 2^16.
But the code becomes incorrect when the period length approaches 1 second.
That's because of things like NS_PER_SEC / period.
[*] At the same time I must note that the KPI provides for maximum
period of about 4 seconds (2^32 nanoseconds).
MFC after: 2 weeks
If a FUSE server returns FOPEN_DIRECT_IO in response to FUSE_OPEN, that
instructs the kernel to bypass the page cache for that file. This feature
is also known by libfuse's name: "direct_io".
However, when accessing a file via mmap, there is no possible way to bypass
the cache completely. This change fixes a deadlock that would happen when
an mmap'd write tried to invalidate a portion of the cache, wrongly assuming
that a write couldn't possibly come from cache if direct_io were set.
Arguably, we could instead disable mmap for files with FOPEN_DIRECT_IO set.
But allowing it is less likely to cause user complaints, and is more in
keeping with the spirit of open(2), where O_DIRECT instructs the kernel to
"reduce", not "eliminate" cache effects.
PR: 247276
Reported by: trapexit@spawn.link
Reviewed by: cem
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D26485
Add EXAMPLES section showing the use of -a and -s flags and how which(1)
treates duplicates.
Approved by: manpages (gbe@)
Differential Revision: https://reviews.freebsd.org/D26182
We have (two versions) of MS() and SM() macros which we use throughout
the wireless code. Change all but three places (ath_hal, rtwn, and rsu)
to the newly provided _IEEE80211_MASKSHIFT() and _IEEE80211_SHIFTMASK()
macros. Also change one internal case using both _S and _M instead of
just _S away from _M (one of the reasons rtwn and rsu were not changed).
This was done semi-mechanically. No functional changes intended.
Requested by: gnn (D26091)
Reviewed by: adrian (pre line wrap)
MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC (d/b/a "Netgate")
Differential Revision: https://reviews.freebsd.org/D26539
- We can exit the loop as soon as the filter check passes.
- The alignment check has already passed so there is no need to also run
it here.
Sponsored by: Innovate UK
We need to use a bounce buffer when the memory we are operating on is not
aligned to a cacheline, and not aligned to the maps alignment.
The former is to stop other threads from dirtying the cacheline while we
are performing DMA operations with it. The latter is to check memory
passed in by a driver is correctly aligned for the device.
Reviewed by: mmel
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D26496
This will ensure nothing modifies the cacheline while DMA is in progress
so we won't need to bounce the data.
Reviewed by: mmel
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D26495
_STANDALONE is only for the bootloader, not kernel modules. Remove it
from the build. This was harmless before, but sys/malloc.h now does
different things for the standalone environment, triggering the issue.
Use it to decide if we can skip cache management.
While here remove the DMAMAP_COULD_BOUNCE flag as it's unneeded.
Reviewed by: mmel
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D26494
Add helper functions to the arm64 busdma for common cases of checking if
we may need to bounce, and if we must bounce for a given address.
These will be expanded later as we handle cache-misaligned memory.
Reported by: mmel
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D26493
The ZSTD support for the boot loader will need to include files that
use the kernel's malloc interface. Create a standalone stub version
that's functional enough to allow this to work. There's some
limitations in this interface, and it's not quite a perfect
match. Specifically, M_WAITOK allocations can fail because there's
nothing that can be done we no memory is available.
It is only ever called for negative entries and for those it is
just a wrapper around cache_zap_negative_locked_vnode_kl which
always succeeds.
This also fixes a bug where cache_lookup_fallback should have been
calling cache_zap_locked_bucket instead. Note that in order to trigger
the bug NOCACHE must not be set, which currently only happens when
creating a new coredump (and then the coredump-to-be has to have a
negative entry).
received.
The default system log rotation mechanism (newsyslog(8)) requires ability to send
signal to a daemon in order to properly complete rotation of the logs in an "atomic"
manner without having to making a copy and truncating original file. Unfortunately
our built-in mechanism to convert "dumb" programs into daemons has no way to handle
this rotation properly. This change adds this ability, to be enabled by supplying -H
option in addition to the -o option.
Reviewed by: markj, rpokala (manpages)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26526
memfd_create is implemented on top of posixshm, so this is a logically
correct place for them to be. Moreover, this reduces the number of places to
look to run tests when working in this part of the tree.
Discussed with: kib (to some extent, a while ago)
The NOTES files have a bunch of hint lines that are removed when
generating LINT. However, we can achieve the same effect by prepending
each of the lines with 'envvar' so the NOTES files become standard
config(8) files. No functional changes as the sed script to generate
the LINT files filters these either way.
Suggested by: kevans
