> Hi Pavel, > > I think this makes a lot of sense. > Since Naoya is out until Wednesday, maybe I give it a shot next week and see if I can gather some numbers. Hi Oscar, Thank you for the offer to do this. Since, sched_clock() is not yet initialized at the time zero_resv_unavail() is called, it is difficult to measure it during boot. But, I had x86 early boot timestamps patches handy, so I could measure, thus decided to submit the patch. http://lkml.kernel.org/r/20180615155733.1175-1-pasha.tatashin@xxxxxxxxxx Thank you, Pavel > > > > > Thank you, > > Pasha > > > > > > > > > --- > > > > arch/x86/kernel/e820.c | 15 ++++++++++++--- > > > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c > > > > index d1f25c831447..c88c23c658c1 100644 > > > > --- a/arch/x86/kernel/e820.c > > > > +++ b/arch/x86/kernel/e820.c > > > > @@ -1248,6 +1248,7 @@ void __init e820__memblock_setup(void) > > > > { > > > > int i; > > > > u64 end; > > > > + u64 addr = 0; > > > > > > > > /* > > > > * The bootstrap memblock region count maximum is 128 entries > > > > @@ -1264,13 +1265,21 @@ void __init e820__memblock_setup(void) > > > > struct e820_entry *entry = &e820_table->entries[i]; > > > > > > > > end = entry->addr + entry->size; > > > > + if (addr < entry->addr) > > > > + memblock_reserve(addr, entry->addr - addr); > > > > + addr = end; > > > > if (end != (resource_size_t)end) > > > > continue; > > > > > > > > + /* > > > > + * all !E820_TYPE_RAM ranges (including gap ranges) are put > > > > + * into memblock.reserved to make sure that struct pages in > > > > + * such regions are not left uninitialized after bootup. > > > > + */ > > > > if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN) > > > > - continue; > > > > - > > > > - memblock_add(entry->addr, entry->size); > > > > + memblock_reserve(entry->addr, entry->size); > > > > + else > > > > + memblock_add(entry->addr, entry->size); > > > > } > > > > > > > > /* Throw away partial pages: */ > > > > -- > > > > 2.7.4 > > > > > > -- > > > Michal Hocko > > > SUSE Labs > > > > > > > Best Regards > Oscar Salvador >
