Messages in this thread | | | Date | Wed, 14 Mar 2018 15:13:23 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH] Revert "mm/page_alloc: fix memmap_init_zone pageblock alignment" |
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Does http://lkml.kernel.org/r/20180313224240.25295-1-neelx@redhat.com fix your issue? From the debugging info you provided it should because the patch prevents jumping backwards.
On Wed 14-03-18 13:44:31, Ard Biesheuvel wrote: > This reverts commit 864b75f9d6b0100bb24fdd9a20d156e7cda9b5ae. > > It breaks the boot on my Socionext SynQuacer based system, because > it enters an infinite loop iterating over the pfns. > > Adding the following debug output to memmap_init_zone() > > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5365,6 +5365,11 @@ > * the valid region but still depends on correct page > * metadata. > */ > + pr_err("pfn:%lx oldnext:%lx newnext:%lx\n", pfn, > + memblock_next_valid_pfn(pfn, end_pfn) - 1, > + (memblock_next_valid_pfn(pfn, end_pfn) & > + ~(pageblock_nr_pages-1)) - 1); > + > pfn = (memblock_next_valid_pfn(pfn, end_pfn) & > ~(pageblock_nr_pages-1)) - 1; > #endif > > results in > > Booting Linux on physical CPU 0x0000000000 [0x410fd034] > Linux version 4.16.0-rc5-00004-gfc6eabbbf8ef-dirty (ard@dogfood) ... > Machine model: Socionext Developer Box > earlycon: pl11 at MMIO 0x000000002a400000 (options '') > bootconsole [pl11] enabled > efi: Getting EFI parameters from FDT: > efi: EFI v2.70 by Linaro > efi: SMBIOS 3.0=0xff580000 ESRT=0xf9948198 MEMATTR=0xf83b1a98 RNG=0xff7ac898 > random: fast init done > efi: seeding entropy pool > esrt: Reserving ESRT space from 0x00000000f9948198 to 0x00000000f99481d0. > cma: Reserved 16 MiB at 0x00000000fd800000 > NUMA: No NUMA configuration found > NUMA: Faking a node at [mem 0x0000000000000000-0x0000000fffffffff] > NUMA: NODE_DATA [mem 0xffffd8d80-0xffffda87f] > Zone ranges: > DMA32 [mem 0x0000000080000000-0x00000000ffffffff] > Normal [mem 0x0000000100000000-0x0000000fffffffff] > Movable zone start for each node > Early memory node ranges > node 0: [mem 0x0000000080000000-0x00000000febeffff] > node 0: [mem 0x00000000febf0000-0x00000000fefcffff] > node 0: [mem 0x00000000fefd0000-0x00000000ff43ffff] > node 0: [mem 0x00000000ff440000-0x00000000ff7affff] > node 0: [mem 0x00000000ff7b0000-0x00000000ffffffff] > node 0: [mem 0x0000000880000000-0x0000000fffffffff] > Initmem setup node 0 [mem 0x0000000080000000-0x0000000fffffffff] > pfn:febf0 oldnext:febf0 newnext:fe9ff > pfn:febf0 oldnext:febf0 newnext:fe9ff > pfn:febf0 oldnext:febf0 newnext:fe9ff > etc etc > > and the boot never proceeds after this point. > > So the logic is obviously flawed, and so it is best to revert this at > the current -rc stage (unless someone can fix the logic instead) > > Fixes: 864b75f9d6b0 ("mm/page_alloc: fix memmap_init_zone pageblock alignment") > Cc: Daniel Vacek <neelx@redhat.com> > Cc: Mel Gorman <mgorman@techsingularity.net> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Paul Burton <paul.burton@imgtec.com> > Cc: Pavel Tatashin <pasha.tatashin@oracle.com> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > mm/page_alloc.c | 9 ++------- > 1 file changed, 2 insertions(+), 7 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 3d974cb2a1a1..cb416723538f 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5359,14 +5359,9 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > /* > * Skip to the pfn preceding the next valid one (or > * end_pfn), such that we hit a valid pfn (or end_pfn) > - * on our next iteration of the loop. Note that it needs > - * to be pageblock aligned even when the region itself > - * is not. move_freepages_block() can shift ahead of > - * the valid region but still depends on correct page > - * metadata. > + * on our next iteration of the loop. > */ > - pfn = (memblock_next_valid_pfn(pfn, end_pfn) & > - ~(pageblock_nr_pages-1)) - 1; > + pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1; > #endif > continue; > } > -- > 2.15.1 >
-- Michal Hocko SUSE Labs
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