The check existed for musl. Let's remove it, as we explicitly request glibc.
While removing the check, this also drops generic_mallinfo, introduces
a tiny converter from struct mallinfo to struct mallinfo2 if mallinfo2()
does not exist, and renames mallinfo-util.h to malloc.h.
With this change, we can drop many ifdefs and casts in .c files.
As explained in https://lore.kernel.org/all/20250419183545.1982187-1-shakeel.butt@linux.dev/,
writing to memory.max or memory.high triggers synchronous memory reclaim
if the limit is lowered. This can end up taking nonnegligible amounts
of time, completely blocking pid1 from doing any other work while the
reclaim is ongoing.
To address this problem, the kernel going to add O_NONBLOCK semantics
to memory.max and memory.high. If the file is opened with O_NONBLOCK,
the synchronous memory reclaim is skipped and only triggered later
without blocking the process writing the file. Let's make sure we make
use of this by opening cgroupv2 attribute files with O_NONBLOCK.
We opt to do this for all cgroupv2 attribute files, to make sure that
if the same problem happens elsewhere in the future and is fixed in the
same way, we immediately take advantage of that fix without having to
make changes in systemd as well. We probably never want to block when
writing cgroupv2 attributes and any cases where we do want to block should
indicate so explicitly instead of blocking by default.
- config.h is not necessary when generating lists, hence drop it.
- linux/audit.h and libaudit.h are included by missing_audit.h,
hence not necessary to include them explicitly.
The header uses __THROW, which is defined in features.h, to make the
header self-consistent.
Note, src/basic/include/sys/mount.h also uses __THROW, and includes
features.h.
It provides several important constants, especially _PATH_BSHELL, which
is used in PID1, executor, and run. The header has been included
indirectly through e.g. libmount.h, mntent.h, utmpx.h, and so on.
Let's explicitly include it in forward.h, as libmount.h and friends that
includes paths.h are irrelevant to _PATH_BSHELL, and we may easily fail
to build when code is touched.
The header is not heavy, hence should not hurt anything.
I'd like to introduce a libsystemd helper for acquiring pidfd
inode id, which however means the fd passed to pidfd_check_pidfs()
can no longer be trusted. Let's add back the logic of allocating
a genuine pidfd allocated internally, which was remove in
5dc9d5b4ea.
Let's rename the return parameters as "ret_xyz" systematically in
sd-login.
Also, let's make the return parameters systematically optional, like we
typically do these days. So far some where optional, other's weren't.
Let's clean this up.
If the first call to `loop_read()` returns 0 (no input), `total_in`
remains 0, causing `total_out/total_in` to potential divide by zero.
We add a check before logging the compression ratio to skip the
percentage calculation when total_in is zero.
Co-authored-by: jinyaoguo <guo846@purdue.edu>
I wanted to see if moving moving out constant string arguments our of
error messages results in smaller binary sizes. Turns out it does, but
the savings are not consistent. Sometimes we get a few kB in a single
binary, sometimes there is no size change.
In multi-seat scenarios, a display manager might need to start multiple
greeter sessions. But systemd allows at most one graphical session per
user. So, display managers now have a range of UIDs to dynamically
allocate users for their greeter sessions.
git grep -l 'Failed to open /'|xargs sed -r -i 's|"Failed to open (/[^ ]+): %m"|"Failed to open %s: %m", "\1"|g'
git grep -l $'Failed to open \'/'|xargs sed -r -i $'s|"Failed to open \'(/[^ ]+)\': %m"|"Failed to open %s: %m", "\\1"|g'
git grep -l "Failed to open /"|xargs sed -r -i $'s|"Failed to open (/[^ ]+), ignoring: %m"|"Failed to open %s, ignoring: %m", "\\1"|g'
+ some manual fixups.
This code seems to work quickly and nicely for a bunch of modern
terminals. Setting $TERM automatically removes an common annoyance for
users. This code will not work for all terminal emulators, but by adding
it in systemd we'll entice maintainers of those terminals to add support
for the sequences. For the terminals that don't support the sequence, we
get a bit of a slowdown of `< 1 ms`, which seems hardly noticeable. The
user can always set TERM explicitly to avoid this if upgrading to a
newer terminal emulator is not possible.
Closes https://github.com/systemd/systemd/issues/36994.
query_term_for_tty() is used in two places: in fixup_environment(),
which affects PID1 itself, and in build_environment(), which affects
spawned services. There is obviously some cost to the extra call,
but I think it's worthwhile to do it. When $TERM is set incorrectly,
basic output works OK, but then there are various annoying corner
cases. In particular, we get the support for color (or lack of it)
wrong, and when output is garbled, users are annoyed. Things like
text editors are almost certain to behave incorrectly. Testing in
test-terminal-util indicates that the time required to make a successful
query is on the order of a dozen microseconds, and an unsuccessful
query costs as much as our timeout, i.e. currently 1/3 ms. I think
this is an acceptable tradeoff.
No caching is used, because fixup_environment() is only called once,
and the other place in build_environment(), only affects services
which are connected to a tty, which is only a handful of services,
and often only started in special circumstances.
Fixes https://github.com/systemd/systemd/issues/36994.
Yu Watanabe
Daan De Meyer
Lennart Poettering
Mike Yuan
Jelle van der Waa
Alexandjinyaoguo
Zbigniew Jędrzejewski-Szmek
Adrian Vovk