This patch is not working well on actual machines. While it worked fine in qemu, on real machines with multi-gigabytes of memory, attempting to boot it up with limited memory (while max_paddr is still quite high) is not working well; I assume it is because the arrays based on max_paddr eg "struct page" etc is consuming too much memory.
I will try to limit max_paddr and see if that works better. Does akaros already take a mem= option that I can use instead? On Mon, Feb 29, 2016 at 12:43 PM, ron minnich <[email protected]> wrote: > Could we, instead, just have a mem= boot time command line parameter? > > ron > > On Mon, Feb 29, 2016 at 11:02 AM 'Kanoj Sarcar' via Akaros < > [email protected]> wrote: > >> Developer tool to limit RAM used (eg to restrict to only node0 memory >> etc). >> >> Signed-off-by: Kanoj Sarcar <[email protected]> >> --- >> kern/arch/x86/page_alloc.c | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/kern/arch/x86/page_alloc.c b/kern/arch/x86/page_alloc.c >> index da3d8b0..ad0aaa4 100644 >> --- a/kern/arch/x86/page_alloc.c >> +++ b/kern/arch/x86/page_alloc.c >> @@ -48,6 +48,10 @@ static bool pa64_is_in_kernel(uint64_t paddr) >> return (EXTPHYSMEM <= paddr) && (paddr < PADDR(end)); >> } >> >> +#define MAX_LIMIT_RAM 0xFFFFFFFFFFFFFFFFULL >> +static uint64_t max_usable_paddr = MAX_LIMIT_RAM; /* cmdline >> option? */ >> +#define USABLE_RAM(_pa_) ((_pa_) < max_usable_paddr) >> + >> /* Helper. For every page in the entry, this will determine whether or >> not the >> * page is free, and handle accordingly. All pages are marked as busy by >> * default, and we're just determining which of them could be free. */ >> @@ -89,6 +93,11 @@ static void parse_mboot_region(struct >> multiboot_mmap_entry *entry, void *data) >> * bootzone. If it was in the bootzone, we already >> skipped it. */ >> if (pa64_is_in_kernel(i)) >> continue; >> + >> + /* If beyond what we want to allocate, give up */ >> + if (!USABLE_RAM(i)) >> + return; >> + >> track_free_page(pa64_to_page(i)); >> } >> } >> @@ -98,6 +107,10 @@ static void check_range(uint64_t start, uint64_t end, >> int expect) >> int ref; >> if (PGOFF(start)) >> printk("Warning: check_range given unaligned addr >> 0x%016llx\n", start); >> + >> + if ((expect == 0) && (!USABLE_RAM(end))) >> + end = max_usable_paddr; >> + >> for (uint64_t i = start; i < end; i += PGSIZE) { >> ref = kref_refcnt(&pa64_to_page(i)->pg_kref); >> if (ref != expect) { >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Akaros" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > -- Thanks, Kanoj -- You received this message because you are subscribed to the Google Groups "Akaros" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. For more options, visit https://groups.google.com/d/optout.
