On 2026-08-20 Pádraig Brady wrote: > Re syscall overhead, it's unfortunate, but I don't see a way around > that at present.
The syscall count in get_cgroup2_cpu_quota could be reduced by 25 % by avoiding stdio. With glibc, fopen + getline + fclose is four syscalls: openat + fstat + read + close. Using open + read + close would need only three. > I do note that sort(1) uses both nproc() and physmem_total(), which > suggests a shared or cached interface may be useful, but that can > come at a later stage. One could cache the mount point and the cgroup path from /proc/self/cgroup. It would typically save 4-5 syscalls. I don't know if it's worth the extra code. "sort /dev/null" (coreutils 9.11) makes over 40 rt_sigaction syscalls, so in sort(1) the cgroup related syscalls aren't so large portion of the total syscall count. -- Lasse Collin
