On 03.12.20 13:52, Paul Menzel wrote: > Dear David, > > > Thank you for the quick response. > > > Am 03.12.20 um 13:25 schrieb David Hildenbrand: >> On 03.12.20 11:51, Paul Menzel wrote: > >>> I am trying to reduce the startup time of Debian’s Linux 5.9.9 on a >>> Intel Kaby Lake system with 32 GB of memory (TUXEDO Book BU1406 (Clevo >>> N240BU)). > > […] > >> We do have deferred meminit in the kernel during boot that can >> initialize memory in parallel. > > Is that used automatically, or do I need to activate it somehow? If your kernel is compiled with CONFIG_DEFERRED_STRUCT_PAGE_INIT it should be enabled automatically. config DEFERRED_STRUCT_PAGE_INIT bool "Defer initialisation of struct pages to kthreads" depends on SPARSEMEM depends on !NEED_PER_CPU_KM depends on 64BIT select PADATA help Ordinarily all struct pages are initialised during early boot in a single thread. On very large machines this can take a considerable amount of time. If this option is set, large machines will bring up a subset of memmap at boot and then initialise the rest in parallel. This has a potential performance impact on tasks running early in the lifetime of the system until these kthreads finish the initialisation. -- Thanks, David / dhildenb
