Messages in this thread | | | Subject | Re: [PATCH 1/4] mm/page_alloc: always initialize memory map for the holes | From | Guenter Roeck <> | Date | Sat, 31 Jul 2021 12:11:16 -0700 |
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Hi,
On 7/31/21 11:30 AM, Mike Rapoport wrote: > On Sat, Jul 31, 2021 at 09:56:01AM -0700, Guenter Roeck wrote: >> Hi, >> >> On Wed, Jul 14, 2021 at 03:37:36PM +0300, Mike Rapoport wrote: >>> From: Mike Rapoport <rppt@linux.ibm.com> >>> >>> Currently memory map for the holes is initialized only when SPARSEMEM >>> memory model is used. Yet, even with FLATMEM there could be holes in the >>> physical memory layout that have memory map entries. >>> >>> For instance, the memory reserved using e820 API on i386 or >>> "reserved-memory" nodes in device tree would not appear in memblock.memory >>> and hence the struct pages for such holes will be skipped during memory map >>> initialization. >>> >>> These struct pages will be zeroed because the memory map for FLATMEM >>> systems is allocated with memblock_alloc_node() that clears the allocated >>> memory. While zeroed struct pages do not cause immediate problems, the >>> correct behaviour is to initialize every page using __init_single_page(). >>> Besides, enabling page poison for FLATMEM case will trigger >>> PF_POISONED_CHECK() unless the memory map is properly initialized. >>> >>> Make sure init_unavailable_range() is called for both SPARSEMEM and FLATMEM >>> so that struct pages representing memory holes would appear as PG_Reserved >>> with any memory layout. >>> >>> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> >> >> This patch causes microblaze petalogix-ml605 qemu emulations to fail >> silently (no console output). Reverting it fixes the problem. > > It appears that petalogix-ml605 memory starts at 0x50000, but microblaze's > pfn_valid does not reject pfns < ARCH_PFN_OFFSET. > > This should fix the issue: > > diff --git a/arch/microblaze/include/asm/page.h b/arch/microblaze/include/asm/page.h > index ce550978f4fc..4b8b2fa78fc5 100644 > --- a/arch/microblaze/include/asm/page.h > +++ b/arch/microblaze/include/asm/page.h > @@ -112,8 +112,7 @@ extern int page_is_ram(unsigned long pfn); > # define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT) > > # define ARCH_PFN_OFFSET (memory_start >> PAGE_SHIFT) > -# define pfn_valid(pfn) ((pfn) < (max_mapnr + ARCH_PFN_OFFSET)) > - > +# define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (max_mapnr + ARCH_PFN_OFFSET)) > # endif /* __ASSEMBLY__ */ > > #define virt_addr_valid(vaddr) (pfn_valid(virt_to_pfn(vaddr)))
Indeed, that does the trick.
Feel free to add
Tested-by: Guenter Roeck <linux@roeck-us.net>
to the patch.
Thanks, Guenter
>> Guenter >> >> --- >> Bisect log: >> >> # bad: [8d4b477da1a807199ca60e0829357ce7aa6758d5] Add linux-next specific files for 20210730 >> # good: [ff1176468d368232b684f75e82563369208bc371] Linux 5.14-rc3 >> git bisect start 'HEAD' 'v5.14-rc3' >> # good: [8f3eb1f5c702ef868d89799b03c21d122f2fe197] Merge remote-tracking branch 'bpf-next/for-next' >> git bisect good 8f3eb1f5c702ef868d89799b03c21d122f2fe197 >> # good: [32286c7080c56c835f25302c38eebccf41b7b576] Merge remote-tracking branch 'tip/auto-latest' >> git bisect good 32286c7080c56c835f25302c38eebccf41b7b576 >> # good: [70c40604c7d393f95171f49717a27bf8e05b5439] Merge remote-tracking branch 'dmaengine/next' >> git bisect good 70c40604c7d393f95171f49717a27bf8e05b5439 >> # good: [b038834891b35ec410693028a500f769db132a81] Merge remote-tracking branch 'rust/rust-next' >> git bisect good b038834891b35ec410693028a500f769db132a81 >> # bad: [d8f4e506a9ba375110945d75573b3304491e6350] memory-hotplug.rst: complete admin-guide overhaul >> git bisect bad d8f4e506a9ba375110945d75573b3304491e6350 >> # good: [bef692dcfb7cdb5c960abfc31e2386a0ff41af54] lazy tlb: shoot lazies, a non-refcounting lazy tlb option >> git bisect good bef692dcfb7cdb5c960abfc31e2386a0ff41af54 >> # bad: [5fcd957e2f0dc4cb25a6ee60ebfb1200de09c9d1] mm-migrate-demote-pages-during-reclaim-v11 >> git bisect bad 5fcd957e2f0dc4cb25a6ee60ebfb1200de09c9d1 >> # good: [8c2a82ab20eb09d217446989ae209f5ff19a64ac] mm/vmalloc: use batched page requests in bulk-allocator >> git bisect good 8c2a82ab20eb09d217446989ae209f5ff19a64ac >> # bad: [c36a5446e29f1461780b06785769b9402522f847] mm/page_alloc.c: fix 'zone_id' may be used uninitialized in this function warning >> git bisect bad c36a5446e29f1461780b06785769b9402522f847 >> # good: [05e358c552628e26be3985933bea88e7512414c0] mm/kasan: move kasan.fault to mm/kasan/report.c >> git bisect good 05e358c552628e26be3985933bea88e7512414c0 >> # bad: [b467ff7f560908e60ca181658b7ee48e5da94da1] microblaze: simplify pte_alloc_one_kernel() >> git bisect bad b467ff7f560908e60ca181658b7ee48e5da94da1 >> # bad: [d2a572bf593a57246827bd79c91fe2ee6b7af1f0] mm/page_alloc: always initialize memory map for the holes >> git bisect bad d2a572bf593a57246827bd79c91fe2ee6b7af1f0 >> # first bad commit: [d2a572bf593a57246827bd79c91fe2ee6b7af1f0] mm/page_alloc: always initialize memory map for the holes >
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