Add a helper that tries to determine the number of installed CPUs. This
borrows heavily from physical_memory(), i.e. uses the physical number,
but caps by per-container cpuset.
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
cpu_set_add_range() is used in parse_cpu_set(), hence already tested.
But it is better to test these functions explicitly.
For CID#1611787 and CID#1611788, that should be false-positive.
Then, make parse_cpu_set() as a tiny wrapper of it.
Note, previously when an invalid CPU range, e.g. "3-0", is specified,
we ignore the range but allocate an empty set. But, with this commit,
now the conf parser simply ignore it without no side effect.
This potentially changes behavior of a system with such invalid setting,
but the change should be favorable for consistency with other parsers.
- introduce CPU_SET_MAX_NCPU and check overflow several more places,
- use GREEDY_REALLOC0(),
- introduce cpu_set_add_range() helper function,
- explicitly (re)alloc first before setting multiple bits.
No functional change, just refactoring.
Takes a list of CPU indices or ranges separated by either whitespace or commas. Alternatively,
takes the special value "all" in which will include all available CPUs in the mask.
CPU ranges are specified by the lower and upper CPU indices separated by a dash (e.g. "2-6").
This option may be specified more than once, in which case the specified CPU affinity masks are merged.
If an empty string is assigned, the mask is reset, all assignments prior to this will have no effect.
Defaults to unset and RPS CPU list is unchanged. To disable RPS when it was previously enabled, use the
special value "disable".
Currently, this will set CPU mask to all `rx` queue of matched device (if it has multiple queues).
The `/sys/class/net/<dev>/queues/rx-<n>/rps_cpus` only accept cpu bitmap mask in hexadecimal.
Fix: #30323
Make possible to set NUMA allocation policy for manager. Manager's
policy is by default inherited to all forked off processes. However, it
is possible to override the policy on per-service basis. Currently we
support, these policies: default, prefer, bind, interleave, local.
See man 2 set_mempolicy for details on each policy.
Overall NUMA policy actually consists of two parts. Policy itself and
bitmask representing NUMA nodes where is policy effective. Node mask can
be specified using related option, NUMAMask. Default mask can be
overwritten on per-service level.
cpu_set_malloc() was the last user. It doesn't seem useful to keep
it just to save the allocation of a few hundred bytes in a test, so
it is dropped and a fixed maximum is allocated (1024 bytes).
The CPU_SET_S api is pretty bad. In particular, it has a parameter for the size
of the array, but operations which take two (CPU_EQUAL_S) or even three arrays
(CPU_{AND,OR,XOR}_S) still take just one size. This means that all arrays must
be of the same size, or buffer overruns will occur. This is exactly what our
code would do, if it received an array of unexpected size over the network.
("Unexpected" here means anything different from what cpu_set_malloc() detects
as the "right" size.)
Let's rework this, and store the size in bytes of the allocated storage area.
The code will now parse any number up to 8191, independently of what the current
kernel supports. This matches the kernel maximum setting for any architecture,
to make things more portable.
Fixes#12605.
This doesn't have much effect on the final build, because we link libbasic.a
into libsystemd-shared.so, so in the end, all the object built from basic/
end up in libsystemd-shared. And when the static library is linked into binaries,
any objects that are included in it but are not used are trimmed. Hence, the
size of output artifacts doesn't change:
$ du -sb /var/tmp/inst*
54181861 /var/tmp/inst1 (old)
54207441 /var/tmp/inst1s (old split-usr)
54182477 /var/tmp/inst2 (new)
54208041 /var/tmp/inst2s (new split-usr)
(The negligible change in size is because libsystemd-shared.so is bigger
by a few hundred bytes. I guess it's because symbols are named differently
or something like that.)
The effect is on the build process, in particular partial builds. This change
effectively moves the requirements on some build steps toward the leaves of the
dependency tree. Two effects:
- when building items that do not depend on libsystemd-shared, we
build less stuff for libbasic.a (which wouldn't be used anyway,
so it's a net win).
- when building items that do depend on libshared, we reduce libbasic.a as a
synchronization point, possibly allowing better parallelism.
Method:
1. copy list of .h files from src/basic/meson.build to /tmp/basic
2. $ for i in $(grep '.h$' /tmp/basic); do echo $i; git --no-pager grep "include \"$i\"" src/basic/ 'src/lib*' 'src/nss-*' 'src/journal/sd-journal.c' |grep -v "${i%.h}.c";echo ;done | less