pmap_remove_all() must not be called on fictitious pages. To date,
fictitious pages have been allocated from zeroed memory, effectively
hiding this problem because the fictitious pages appear to have an empty
pv list. Submitted by: Kostik Belousov
Rewrite the comments describing vm_object_page_remove() to better
describe what it does. Add an assertion. Reviewed by: Kostik Belousov
MFC after: 1 week
the vnode interlock is not held. vn_printf() already correctly handles
locked and unlocked vnode interlocks, and all the in-tree vop_print
methods are interlock-agnostic.
Some code calls vprintf() with the vnode interlock held, that causes
unjustified panics with INVARIANTS (ffs_syncvnode() as example).
Reported by: Peter Holm
number read from cylinder group. Chances that we read a smarshed
cylinder group, and we can not 100% trust information it has
supplied. fsck_ffs(8) will crash otherwise for some cases.
processing the information. chk1 is more prone to crash when insane
information is provided by the on-disk inode, and does not even work
if the inode is being smarshed badly.
whether fs_bsize is larger than MINBSIZE, which is larger than the
value that is used to compared with fs_bsize, the sizeof fs, so the
check followed, will be always true.
By inspecting the code and some old commit log, I believe that the
check must be that *fs_sbsize* is larger than sizeof fs. We round
up the size to nearest dev_bsize, as the smallest accepted fs_sbsize,
personally, I think this can be even changed to equal, because this
number is mostly an invariant in file systems.
With this check, fsck_ffs(8) will be more picky and has better
chance rejecting bad first superblock rather than referring to bad
value it supplied, thus gives better chance for it to check the
filesystem carefully.
want to adjust this code to just assume that all CPUs >= Esther should
be checked for the extended cpuid flags register.
MFC after: 3 days
PR: i386/119491
gives an average speedup of about 12 cycles or 17% for
9pi/4 < |x| <= 2**19pi/2 and a smaller speedup for larger x, and a
small speeddown for |x| <= 9pi/4 (only 1-2 cycles average, but that
is 4%).
Inlining this is less likely to bust caches than inlining the float
version since it is much smaller (about 220 bytes text and rodata) and
has many fewer branches. However, the float version was already large
due to its manual inlining of the branches and also the polynomial
evaluations.
The code seems pretty MPSAFE and Giant is held over kproc_exit() which
at lowel calls exit1(). exit1() requires Giant to be unowned so this
opens a window for races.
Reported by: Bryan Venteicher <bryanv at daemoninthecloset dot org>
Tested by: Bryan Venteicher <bryanv at daemoninthecloset dot org>
of the GNU utility. The default behavior of our original `du' is to
count hardlinked files only once for each invocation of the utility.
With the new -l option they count towards the final size every time
they are found.
PR: bin/117944
Submitted by: keramida
Reviewed by: des, obrien
MFC after: 2 weeks
always curthread.
As KPI gets broken by this patch, manpages and __FreeBSD_version will be
updated by further commits.
Tested by: Andrea Barberio <insomniac at slackware dot it>
__kernel_rem_pio2(). This simplifies analysis of aliasing and thus
results in better code for the usual case where __kernel_rem_pio2()
is not called. In particular, when __ieee854_rem_pio2[f]() is inlined,
it normally results in y[] being returned in registers. I couldn't
get this to work using the restrict qualifier.
In float precision, this saves 2-3% in most cases on amd64 and i386
(A64) despite it not being inlined in float precision yet. In double
precision, this has high variance, with an average gain of 2% for
amd64 and 0.7% for i386 (but a much larger gain for usual cases) and
some losses.
source upgrades by falling back to GNU ar(1) as necessary. Option
WITH_BSDAR is gone. Option _WITH_GNUAR to aid in upgrades is *not*
supposed to be set by the user.
Stop bootstrapping BSD ar(1) on the next __FreeBSD_version bump, as
there are no known bugs in it. Bump __FreeBSD_version to anticipate
this and to flag the switch to BSD ar(1), should it be needed for
something.
Input from: obrien, des, kaiw
first before they can be set to Explorer mode.
PR: kern/118578
Submitted by: Andriy Gapon <avg@icyb.net.ua> (I added some comments)
Reviewed by: philip
MFC after: 1 month
this function and its callers cosf(), sinf() and tanf() don't waste time
converting values from doubles to floats and back for |x| > 9pi/4.
All these functions were optimized a few years ago to mostly use doubles
internally and across the __kernel*() interfaces but not across the
__ieee754_rem_pio2f() interface.
This saves about 40 cycles in cosf(), sinf() and tanf() for |x| > 9pi/4
on amd64 (A64), and about 20 cycles on i386 (A64) (except for cosf()
and sinf() in the upper range). 40 cycles is about 35% for |x| < 9pi/4
<= 2**19pi/2 and about 5% for |x| > 2**19pi/2. The saving is much
larger on amd64 than on i386 since the conversions are not easy to
optimize except on i386 where some of them are automatic and others
are optimized invalidly. amd64 is still about 10% slower in cosf()
and tanf() in the lower range due to conversion overhead.
This also gives a tiny speedup for |x| <= 9pi/4 on amd64 (by simplifying
the code). It also avoids compiler bugs and/or additional slowness
in the conversions on (not yet supported) machines where double_t !=
double.
e_rem_pio2.c:
Float and double precision didn't work because init_jk[] was 1 too small.
It needs to be 2 larger than you might expect, and 1 larger than it was
for these precisions, since its test for recomputing needs a margin of
47 bits (almost 2 24-bit units).
init_jk[] seems to be barely enough for extended and quad precisions.
This hasn't been completely verified. Callers now get about 24 bits
of extra precision for float, and about 19 for double, but only about
8 for extended and quad. 8 is not enough for callers that want to
produce extra-precision results, but current callers have rounding
errors of at least 0.8 ulps, so another 1/2**8 ulps of error from the
reduction won't affect them much.
Add a comment about some of the magic for init_jk[].
e_rem_pio2.c:
Double precision worked in practice because of a compensating off-by-1
error here. Extended precision was asked for, and it executed exactly
the same code as the unbroken double precision.
e_rem_pio2f.c:
Float precision worked in practice because of a compensating off-by-1
error here. Double precision was asked for, and was almost needed,
since the cosf() and sinf() callers want to produce extra-precision
results, at least internally so that their error is only 0.5009 ulps.
However, the extra precision provided by unbroken float precision is
enough, and the double-precision code has extra overheads, so the
off-by-1 error cost about 5% in efficiency on amd64 and i386.
variations (e500 currently), this provides a gcc-level FPU emulation and is an
alternative approach to the recently introduced kernel-level emulation
(FPU_EMU).
Approved by: cognet (mentor)
MFp4: e500
