This caching allows for completely lock-free allocation/deallocation in the
steady state, at the expense of likely increased memory use and
fragmentation.
Reduce the default number of arenas to 2*ncpus, since thread-specific
caching typically reduces arena contention.
Modify size class spacing to include ranges of 2^n-spaced, quantum-spaced,
cacheline-spaced, and subpage-spaced size classes. The advantages are:
fewer size classes, reduced false cacheline sharing, and reduced internal
fragmentation for allocations that are slightly over 512, 1024, etc.
Increase RUN_MAX_SMALL, in order to limit fragmentation for the
subpage-spaced size classes.
Add a size-->bin lookup table for small sizes to simplify translating sizes
to size classes. Include a hard-coded constant table that is used unless
custom size class spacing is specified at run time.
Add the ability to disable tiny size classes at compile time via
MALLOC_TINY.
is returned shall be kept in the waitable state.
Add WSTOPPED as an alias for WUNTRACED.
Submitted by: Jukka Ukkonen <jau at iki fi>
PR: standards/116221
MFC after: 2 weeks
executed by fexecve(2), imgp->args->fname is NULL. Moreover, there is
no way to recover the path to the script being executed.
Do what some other U*ixes do unconditionally, namely supply /dev/fd/n
as the script path when called from fexecve(). Document requirement of
having fdescfs mounted as caveat.
Since various 'find' incantations can emit container directories
in various orders, we cannot refuse to update a dir because it's
apparently the same age.
MFC after: 3 days
For gcc' __builtin_frame_address() to work, all call frames need to save
frame pointer. In particular, this is important for the upper frame that
should terminate the chain.
No objections from: jhb
PR: amd64/126543
MFC after: 1 week
The routines in grantpt.c have been moved to ptsname.c in the MPSAFE TTY
layer, because grantpt() is now effectively a no-op. I forgot to remove
the corresponding source file from libc.
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
'kern.cp_time'. For a live kernel it uses the sysctl. For a crashdump,
it first checks to see if the kernel has a 'cp_time' global symbol. If
it does, it uses that. If that doesn't work, when it uses the recently
added kvm_getmaxcpu(3) and kvm_getpcpu(3) routines to walk all the CPUs
and sum up their counters.
MFC after: 1 week
uuid_dec_be() functions. These routines are not part of the
DCE RPC API. They are provided for convenience.
Reviewed by: marcel
Obtained from: NetBSD
MFC after: 1 week
detect whether the integer division table is large enough to handle the
divisor. Before this change, the last two table elements were never used,
thus causing the slow path to be used for those divisors.
Right now the bpf(4) driver uses the cloning API to generate /dev/bpf%u.
When an application such as tcpdump needs a BPF, it opens /dev/bpf0,
/dev/bpf1, etc. until it opens the first available device node. We used
this approach, because our devfs implementation didn't allow
per-descriptor data.
Now that we can, make it use devfs_get_cdevpriv() to obtain the private
data. To remain compatible with the existing implementation, add a
symlink from /dev/bpf0 to /dev/bpf. I've already changed libpcap to
compile with HAVE_CLONING_BPF, which makes it use /dev/bpf. There may be
other applications in the base system (dhclient) that use the loop to
obtain a valid bpf.
Discussed on: src-committers
Approved by: csjp
#pragma STDC CX_LIMITED_RANGE ON
the "ON" needs to be in caps. gcc doesn't understand this pragma
anyway and assumes it is always on in any case, but icc supports
it and cares about the case.
conj() instead of using expressions like z * I. The latter is bad for
several reasons:
1. It is implemented using arithmetic, which is unnecessary, and can
generate floating point exceptions, contrary to the requirements on
these functions.
2. gcc implements complex multiplication using a formula that breaks
down for infinities, e.g., it gives INFINITY * I == nan + inf I.
is based on an old implementation from the University of Michigan with lots of
changes and fixes by me and the addition of a Solaris-compatible API.
Sponsored by: Isilon Systems
Reviewed by: alfred
to this commit, "env BLOCKSIZE=4X df" prints not only "4X: unknown
blocksize" as expected, but sometimes also "maximum blocksize is 1G"
and "minimum blocksize is 512" depending on what happened to be on
the stack.
Found by: LLVM/Clang Static Checker
understand which code paths aren't possible.
This commit eliminates 117 false positive bug reports of the form
"allocate memory; error out if pointer is NULL; use pointer".
environ[0] to be more obvious that environ is not NULL before environ[0]
is tested. Although I believe the previous code worked, this change
improves code maintainability.
Reviewed by: ache
MFC after: 3 days
assumed to be reviewd by them):
Stir directly from the kernel PRNG, without taking less random pid & time
bytes too (when it is possible).
The difference with OpenBSD code is that they have KERN_ARND sysctl for
that task, while we need to read /dev/random
- When y/x is huge, it's faster and more accurate to return pi/2
instead of pi - pi/2.
- There's no need for 3 lines of bit fiddling to compute -z.
- Fix a comment.
