When we don't want to use non-temporal stores for memset, we set
`x86_memset_non_temporal_threshold` to SIZE_MAX.
The current code, however, we using `maximum_non_temporal_threshold`
as the upper bound which is `SIZE_MAX >> 4` so we ended up with a
value of `0`.
Fix is to just use `SIZE_MAX` as the upper bound for when setting the
tunable.
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Linux pinacolada 6.6.32-gentoo #1 SMP PREEMPT Sun Jun 9 14:18:17 CEST 2024 x86_64 Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz GenuineIntel GNU/Linux
32bit build for multilib environment
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
"ADDI sp, sp, 24" and "ADDI sp, sp, SZFCSREG" (SZFCSREG = 4) are
misaligning the stack: the ABI mandates a 16-byte alignment. Fix it
by changing the first one to "ADDI sp, sp, 32", and reuse the spare 4th
slot for saving fcsr.
Reported-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Properly set libc_cv_have_x86_isa_level in shell for MINIMUM_X86_ISA_LEVEL
defined as
(__X86_ISA_V1 + __X86_ISA_V2 + __X86_ISA_V3 + __X86_ISA_V4)
Also set __X86_ISA_V2 to 1 for i386 if __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
is defined. There are no changes in config.h nor in config.make on x86-64.
On i386, -march=x86-64-v2 with GCC generates
#define MINIMUM_X86_ISA_LEVEL 2
in config.h and
have-x86-isa-level = 2
in config.make. This fixes BZ #31883.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
The __stack_prot is used by Linux to make the stack executable if
a modules requires it. It is also marked as RELRO, which requires
to change the segment permission to RW to update it.
Also, there is no need to keep track of the flags: either the stack
will have the default permission of the ABI or should be change to
PROT_READ | PROT_WRITE | PROT_EXEC. The only additional flag,
PROT_GROWSDOWN or PROT_GROWSUP, is Linux only and can be deducted
from _STACK_GROWS_DOWN/_STACK_GROWS_UP.
Also, the check_consistency function was already removed some time
ago.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
On i386, set the default minimum ISA level to 0, not 1 (baseline which
includes SSE2). There are no changes in config.h nor in config.make on
x86-64. This fixes BZ #31867.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Tested-by: Ian Jordan <immoloism@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
In commit 46b5e98ef6 ("x86: Add seperate non-temporal tunable for
memset") a tunable threshold for enabling non-temporal memset was added,
but only for Intel hardware.
Since that commit, new benchmark results suggest that non-temporal
memset is beneficial on AMD, as well, so allow this tunable to be set
for AMD.
See:
https://docs.google.com/spreadsheets/d/1opzukzvum4n6-RUVHTGddV6RjAEil4P2uMjjQGLbLcU/edit?usp=sharing
which has been updated to include data using different stategies for
large memset on AMD Zen2, Zen3, and Zen4.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
As of Linux kernel 6.9, some ioctls and a parameters structure have been
introduced which allow user programs to control whether a particular
epoll context will busy poll.
Update the headers to include these for the convenience of user apps.
The ioctls were added in Linux kernel 6.9 commit 18e2bf0edf4dd
("eventpoll: Add epoll ioctl for epoll_params") [1] to
include/uapi/linux/eventpoll.h.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/diff/?h=v6.9&id=18e2bf0edf4dd
Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Left shift of ki is undefined when ki<0, copy the logic from exp,
which uses unsigned arithmetics, to fix it.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The tuning for non-temporal stores for memset vs memcpy is not always
the same. This includes both the exact value and whether non-temporal
stores are profitable at all for a given arch.
This patch add `x86_memset_non_temporal_threshold`. Currently we
disable non-temporal stores for non Intel vendors as the only
benchmarks showing its benefit have been on Intel hardware.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Previously we use `rep stosb` for all medium/large memsets. This is
notably worse than non-temporal stores for large (above a
few MBs) memsets.
See:
https://docs.google.com/spreadsheets/d/1opzukzvum4n6-RUVHTGddV6RjAEil4P2uMjjQGLbLcU/edit?usp=sharing
For data using different stategies for large memset on ICX and SKX.
Using non-temporal stores can be up to 3x faster on ICX and 2x faster
on SKX. Historically, these numbers would not have been so good
because of the zero-over-zero writeback optimization that `rep stosb`
is able to do. But, the zero-over-zero writeback optimization has been
removed as a potential side-channel attack, so there is no longer any
good reason to only rely on `rep stosb` for large memsets. On the flip
size, non-temporal writes can avoid data in their RFO requests saving
memory bandwidth.
All of the other changes to the file are to re-organize the
code-blocks to maintain "good" alignment given the new code added in
the `L(stosb_local)` case.
The results from running the GLIBC memset benchmarks on TGL-client for
N=20 runs:
Geometric Mean across the suite New / Old EXEX256: 0.979
Geometric Mean across the suite New / Old EXEX512: 0.979
Geometric Mean across the suite New / Old AVX2 : 0.986
Geometric Mean across the suite New / Old SSE2 : 0.979
Most of the cases are essentially unchanged, this is mostly to show
that adding the non-temporal case didn't add any regressions to the
other cases.
The results on the memset-large benchmark suite on TGL-client for N=20
runs:
Geometric Mean across the suite New / Old EXEX256: 0.926
Geometric Mean across the suite New / Old EXEX512: 0.925
Geometric Mean across the suite New / Old AVX2 : 0.928
Geometric Mean across the suite New / Old SSE2 : 0.924
So roughly a 7.5% speedup. This is lower than what we see on servers
(likely because clients typically have faster single-core bandwidth so
saving bandwidth on RFOs is less impactful), but still advantageous.
Full test-suite passes on x86_64 w/ and w/o multiarch.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
A space is added before the left bracket of the x86_64 elf_machine_rela
function, in order to harmonize with the rest of the implementation of
the function and to make it easier to retrieve the function. The lines
where the function definition is located has been re-indented, as well
as its left curly bracket placed in the correct position.
Signed-off-by: Xin Wang <yw987194828@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
pidfd_getpid.c has
/* Ignore invalid large values. */
if (INT_MULTIPLY_WRAPV (10, n, &n)
|| INT_ADD_WRAPV (n, *l++ - '0', &n))
return -1;
For GCC older than GCC 7, INT_ADD_WRAPV(a, b, r) is defined as
_GL_INT_OP_WRAPV (a, b, r, +, _GL_INT_ADD_RANGE_OVERFLOW)
and *l++ - '0' is evaluated twice. Fix BZ #31798 by moving "l++" out of
the if statement. Tested with GCC 6.4 and GCC 14.1.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch updates the kernel version in the tests tst-mman-consts.py
and tst-mount-consts.py to 6.9. (There are no new constants covered
by these tests in 6.9 that need any other header changes;
tst-pidfd-consts.py was updated separately along with adding new
constants relevant to that test.)
Tested with build-many-glibcs.py.
The libc.a for alpha, s390, and sparcv9 does not provide
copysignf64x, copysignf128, frexpf64x, frexpf128, modff64x, and
modff128.
Checked with a static build for the affected ABIs.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Both the generic and POWER6 versions provide definitions of the
symbol, which are already provided by the ifunc resolver.
Checked on powerpc-linux-gnu-power4.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
For powerpc64 the generic version provides a weak definition of
strchrnul, which are already provided by the ifunc resolver. The
powerpc32 version is slight different, where for static case there
is no iFUNC support.
The strncasecmp_l is provided ifunc resolver.
Checked on powerpc-linux-gnu-power4 and powerpc64-linux-gnu.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
The generic version provides weak definitions of memchr/strlen,
which are already provided by the ifunc resolvers.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Linux 6.9 adds some more PIDFD_* constants. Add them to glibc's
sys/pidfd.h, including updating comments that said FLAGS was reserved
and must be 0, along with updating tst-pidfd-consts.py.
Tested with build-many-glibcs.py.
Don't provide __nexttowardf128_do_not_use, nexttowardf128_do_not_use,
finitef128_do_not_use, isinff128_do_not_use and isnanf128_do_not_use.
This fixes BZ #31757.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Some static implementation of float128 routines might call __isnanf128,
which is not provided by the static object.
Checked on x86_64-linux-gnu.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
The commit 08ddd26814 removed the static exp10 on i386 and m68k with an
empty w_exp10.c (required for the ABIs that uses the newly
implementation). This patch fixes by adding the required symbols on the
arch-specific w_exp{f}_compat.c implementation.
Checked on i686-linux-gnu and with a build for m68k-linux-gnu.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
The commit 16439f419b removed the static fmod/fmodf on i386 and m68k
with and empty w_fmod.c (required for the ABIs that uses the newly
implementation). This patch fixes by adding the required symbols on
the arch-specific w_fmod{f}_compat.c implementation.
To statically build fmod fails on some ABI (alpha, s390, sparc) because
it does not export the ldexpf128, this is also fixed by this patch.
Checked on i686-linux-gnu and with a build for m68k-linux-gnu.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
clone3 isn't exported from glibc and is hidden in libc.so. Fix BZ #31770
by removing clone3 alias.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Plus a small amount of moving includes around in order to be able to
remove duplicate definition of asuint64.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Fix BZ #31768 by not defining stpncpy alias when used in IFUNC.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
C23 adds various <math.h> function families originally defined in TS
18661-4. Add the log2p1 functions (log2(1+x): like log1p, but for
base-2 logarithms).
This illustrates the intended structure of implementations of all
these function families: define them initially with a type-generic
template implementation. If someone wishes to add type-specific
implementations, it is likely such implementations can be both faster
and more accurate than the type-generic one and can then override it
for types for which they are implemented (adding benchmarks would be
desirable in such cases to demonstrate that a new implementation is
indeed faster).
The test inputs are copied from those for log1p. Note that these
changes make gen-auto-libm-tests depend on MPFR 4.2 (or later).
The bulk of the changes are fairly generic for any such new function.
(sysdeps/powerpc/nofpu/Makefile only needs changing for those
type-generic templates that use fabs.)
Tested for x86_64 and x86, and with build-many-glibcs.py.
Linux 6.9 has no new syscalls. Update the version number in
syscall-names.list to reflect that it is still current for 6.9.
Tested with build-many-glibcs.py.
Fix BZ #31755 by renaming the internal function procutils_read_file to
__libc_procutils_read_file.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Fix BZ #31759 by not defining nearbyint aliases when used in IFUNC.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This supports common coding patterns. The GCC C front end before
version 7 rejects the may_alias attribute on a struct definition
if it was not present in a previous forward declaration, so this
attribute can only be conditionally applied.
This implements the spirit of the change in Austin Group issue 1641.
Suggested-by: Marek Polacek <polacek@redhat.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Sam James <sam@gentoo.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This patch ensures that $libc_cv_cc_submachine, which is set from
"--with-cpu", overrides $CFLAGS for configure time tests.
Suggested-by: Peter Bergner <bergner@linux.ibm.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
Noah Goldstein
Andreas K. Hüttel
Xi Ruoyao
H.J. Lu
Adhemerval Zanella
Joe Damato
Samuel Thibault
Szabolcs Nagy
Joseph Myers
Xin Wang
Sunil K Pandey
Stefan Liebler
Joe Ramsay
caiyinyu
mengqinggang
Florian Weimer
Manjunath Matti