On 03/04/2020 07:56 AM, Anshuman Khandual wrote: > > > On 03/03/2020 09:58 PM, Catalin Marinas wrote: >> On Tue, Mar 03, 2020 at 09:34:45AM +0530, Anshuman Khandual wrote: >>> On 03/02/2020 11:15 PM, Catalin Marinas wrote: >>>> On Mon, Mar 02, 2020 at 03:54:43PM +0200, Mike Rapoport wrote: >>>>> On Mon, Mar 02, 2020 at 10:47:27AM +0000, Will Deacon wrote: >>>>>> [+Anshuman and Catalin] >>>>>> >>>>>> On Mon, Mar 02, 2020 at 01:58:26PM +0530, Naresh Kamboju wrote: >>>>>>> Linux-Next 20200302 arm64 build failed due to below errors, >>>>>>> Suspecting patch causing this build break. >>>>>>> >>>>>>> 87d900aef3e2 arm/arm64: add support for folded p4d page tables >>>>>>> >>>>>>> Error log, >>>>>>> ------------- >>>>>>> arch/arm64/mm/mmu.c: In function 'unmap_hotplug_pud_range': >>>>>>> include/linux/compiler.h:284:1: error: incompatible type for argument >>>>>>> 1 of 'p4d_page_paddr' >>>>>>> ({ \ >>>>>>> ^ >>>>>>> arch/arm64/include/asm/memory.h:270:45: note: in definition of macro >>>>>>> '__phys_to_virt' >>>>>>> #define __phys_to_virt(x) ((unsigned long)((x) - physvirt_offset)) >>>>>>> ^ >>>>>>> arch/arm64/include/asm/pgtable.h:629:42: note: in expansion of macro '__va' >>>>>>> #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) >>>>>>> ^~~~ >>>>>>> include/linux/compiler.h:293:22: note: in expansion of macro '__READ_ONCE' >>>>>>> #define READ_ONCE(x) __READ_ONCE(x, 1) >>>>>>> ^~~~~~~~~~~ >>>>>>> arch/arm64/include/asm/pgtable.h:628:52: note: in expansion of macro 'READ_ONCE' >>>>>>> #define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir))) >>>>>>> + pud_index(addr) * sizeof(pud_t)) >>>>>>> ^~~~~~~~~ >>>>>>> arch/arm64/include/asm/pgtable.h:629:47: note: in expansion of macro >>>>>>> 'pud_offset_phys' >>>>>>> #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) >>>>>>> ^~~~~~~~~~~~~~~ >>>>>>> arch/arm64/mm/mmu.c:827:10: note: in expansion of macro 'pud_offset' >>>>>>> pudp = pud_offset(pgdp, addr); >>>>>>> ^~~~~~~~~~ >>>>>> >>>>>> Looks like we need an implementation of unmap_hotplug_p4d_range() to >>>>>> walk the dummy p4d level. Unfortunately, we don't have the folded p4d >>>>>> patches in the arm64 tree so we'll either need a common branch or the >>>>>> hotplug patches will need to be dropped for the moment. >>>>> >>>>> unmap_hotplug_p4d_range() is easy :) >>>>> >>>>> From c7a5d08ff51ca2057b6b0289c4423bdfd7643518 Mon Sep 17 00:00:00 2001 >>>>> From: Mike Rapoport <rppt@xxxxxxxxxxxxx> >>>>> Date: Mon, 2 Mar 2020 15:53:17 +0200 >>>>> Subject: [PATCH] arm64/mm: implement unmap_hotplug_p4d_range >>>>> >>>>> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> >>>>> --- >>>>> arch/arm64/mm/mmu.c | 20 +++++++++++++++++++- >>>>> 1 file changed, 19 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >>>>> index 05ec8e5f1436..c76b11577558 100644 >>>>> --- a/arch/arm64/mm/mmu.c >>>>> +++ b/arch/arm64/mm/mmu.c >>>>> @@ -840,6 +840,24 @@ static void unmap_hotplug_pud_range(pgd_t *pgdp, unsigned long addr, >>>>> } while (addr = next, addr < end); >>>>> } >>>>> >>>>> +static void unmap_hotplug_p4d_range(pgd_t *pgd, unsigned long addr, >>>>> + unsigned long end, bool free_mapped) >>>>> +{ >>>>> + unsigned long next; >>>>> + pgd_t *p4dp, p4d; >>>>> + >>>>> + do { >>>>> + next = p4d_addr_end(addr, end); >>>>> + p4dp = p4d_offset(pgd, addr); >>>>> + p4d = READ_ONCE(*p4dp); >>>>> + if (p4d_none(p4d)) >>>>> + continue; >>>>> + >>>>> + WARN_ON(!p4d_present(p4d)); >>>>> + unmap_hotplug_pud_range(p4dp, addr, next, free_mapped); >>>>> + } while (addr = next, addr < end); >>>>> +} >>>>> + >>>>> static void unmap_hotplug_range(unsigned long addr, unsigned long end, >>>>> bool free_mapped) >>>>> { >>>>> @@ -854,7 +872,7 @@ static void unmap_hotplug_range(unsigned long addr, unsigned long end, >>>>> continue; >>>>> >>>>> WARN_ON(!pgd_present(pgd)); >>>>> - unmap_hotplug_pud_range(pgdp, addr, next, free_mapped); >>>>> + unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped); >>>>> } while (addr = next, addr < end); >>>>> } >>>> >>>> Thanks Mike. With the additional diff below, I can get it to build with >>>> and without the p4d clean-up patches in -next. If Anshuman confirms that >>>> they work, I can add them on top of the arm64 for-next/memory-hotremove >>>> branch. >>> >>> These two patches applied on next-20200302 works fine for hot-remove. >> >> Do they also work on top of the vanilla kernel + your hotremove patches >> (i.e. not on top of -next)? > > Yes, they do work on current vanilla kernel (8b614cb8f1dcac8ca77cf4dd85f46) > and v13 hotremove series. > >> >>> As the second patch also fixes the first one, IMHO both should be >>> folded into a single one instead. Just wondering if this combined >>> patch which enables P4D page table should be posted on the list or do >>> I need to respin original hot remove patches again. >> >> If your unmap patches plus the fixes from Mike and me work fine on top >> of 5.6-rc3 (as well as when combined with linux-next), I'd prefer you > Yes, they do work on both. > >> respin your patches to include the p4d support from start. Otherwise, we > > Okay. I will be sending V14 on v5.6-rc3 (OR v.5.6-rc4 is preferred ?) with > p4d support. I will add yours and Mike's Signed-off-by as well. Posted V14 (https://patchwork.kernel.org/project/linux-mm/list/?series=250939) for the arm64 hot remove series on v5.6-rc3, though it also applies and works on 5.6-rc4 as well. > >> create a single patch that Andrew can merge on top of the -mm tree. >>