David Hildenbrand <david@xxxxxxxxxx> writes: > 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. Hello Paul, If it is enabled, what does dmesg | grep 'deferred pages' give you? And assuming you're running systemd, what does systemd-analyze show you? Thanks.
