On Wed, Sep 05, 2018 at 10:47:10AM -0700, Paul Burton wrote: > Hi Mike, > > On Sat, Sep 01, 2018 at 12:17:48AM +0300, Mike Rapoport wrote: > > On Thu, Aug 30, 2018 at 02:48:57PM -0700, Paul Burton wrote: > > > On Mon, Aug 27, 2018 at 10:59:35AM +0300, Mike Rapoport wrote: > > > > MIPS already has memblock support and all the memory is already registered > > > > with it. > > > > > > > > This patch replaces bootmem memory reservations with memblock ones and > > > > removes the bootmem initialization. > > > > > > > > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> > > > > --- > > > > > > > > arch/mips/Kconfig | 1 + > > > > arch/mips/kernel/setup.c | 89 +++++----------------------------- > > > > arch/mips/loongson64/loongson-3/numa.c | 34 ++++++------- > > > > arch/mips/sgi-ip27/ip27-memory.c | 11 ++--- > > > > 4 files changed, 33 insertions(+), 102 deletions(-) > > > > > > Thanks for working on this. Unfortunately it breaks boot for at least a > > > 32r6el_defconfig kernel on QEMU: > > > > > > $ qemu-system-mips64el \ > > > -M boston \ > > > -kernel arch/mips/boot/vmlinux.gz.itb \ > > > -serial stdio \ > > > -append "earlycon=uart8250,mmio32,0x17ffe000,115200 console=ttyS0,115200 debug memblock=debug mminit_loglevel=4" > > > [ 0.000000] Linux version 4.19.0-rc1-00008-g82d0f342eecd (pburton@pburton-laptop) (gcc version 8.1.0 (GCC)) #23 SMP Thu Aug 30 14:38:06 PDT 2018 > > > [ 0.000000] CPU0 revision is: 0001a900 (MIPS I6400) > > > [ 0.000000] FPU revision is: 20f30300 > > > [ 0.000000] MSA revision is: 00000300 > > > [ 0.000000] MIPS: machine is img,boston > > > [ 0.000000] Determined physical RAM map: > > > [ 0.000000] memory: 10000000 @ 00000000 (usable) > > > [ 0.000000] memory: 30000000 @ 90000000 (usable) > > > [ 0.000000] earlycon: uart8250 at MMIO32 0x17ffe000 (options '115200') > > > [ 0.000000] bootconsole [uart8250] enabled > > > [ 0.000000] memblock_reserve: [0x00000000-0x009a8fff] setup_arch+0x224/0x718 > > > [ 0.000000] memblock_reserve: [0x01360000-0x01361ca7] setup_arch+0x3d8/0x718 > > > [ 0.000000] Initrd not found or empty - disabling initrd > > > [ 0.000000] memblock_virt_alloc_try_nid: 7336 bytes align=0x40 nid=-1 from=0x00000000 max_addr=0x00000000 early_init_dt_alloc_memory_arch+0x20/0x2c > > > [ 0.000000] memblock_reserve: [0xbfffe340-0xbfffffe7] memblock_virt_alloc_internal+0x120/0x1ec > > > <hang> > > > > > > It looks like we took a TLB store exception after calling memset() with > > > a bogus address from memblock_virt_alloc_try_nid() or something inlined > > > into it. > > > > Memblock tries to allocate from the top and the resulting address ends up > > in the high memory. > > > > With the hunk below I was able to get to "VFS: Cannot open root device" > > > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > > index 4114d3c..4a9b0f7 100644 > > --- a/arch/mips/kernel/setup.c > > +++ b/arch/mips/kernel/setup.c > > @@ -577,6 +577,8 @@ static void __init bootmem_init(void) > > * Reserve initrd memory if needed. > > */ > > finalize_initrd(); > > + > > + memblock_set_bottom_up(true); > > } > > That does seem to fix it, and some basic tests are looking good. The bottom up mode has the downside of allocating memory below MAX_DMA_ADDRESS. I'd like to check if memblock_set_current_limit(max_low_pfn) will also fix the issue, at least with the limited tests I can do with qemu. > I notice you submitted this as part of your larger series to remove > bootmem - are you still happy for me to take this one through mips-next? Sure, I've just posted it as the part of the larger series for completeness. I believe that in the next few days I'll be able to verify whether memblock_set_current_limit() can be used instead of memblock_set_bottom_up() and I'll resend the patch then. > Thanks, > Paul > -- Sincerely yours, Mike.
