kernel_optimize_test/arch/x86/mm
Jan Beulich a3c6018e56 x86: fix assumed to be contiguous leaf page tables for kmap_atomic region (take 2)
Debugging and original patch from Nick Piggin <npiggin@suse.de>

The early fixmap pmd entry inserted at the very top of the KVA is causing the
subsequent fixmap mapping code to not provide physically linear pte pages over
the kmap atomic portion of the fixmap (which relies on said property to
calculate pte addresses).

This has caused weird boot failures in kmap_atomic much later in the boot
process (initial userspace faults) on a 32-bit PAE system with a larger number
of CPUs (smaller CPU counts tend not to run over into the next page so don't
show up the problem).

Solve this by attempting to clear out the page table, and copy any of its
entries to the new one. Also, add a bug if a nonlinear condition is encountered
and can't be resolved, which might save some hours of debugging if this fragile
scheme ever breaks again...

Once we have such logic, we can also use it to eliminate the early ioremap
trickery around the page table setup for the fixmap area. This also fixes
potential issues with FIX_* entries sharing the leaf page table with the early
ioremap ones getting discarded by early_ioremap_clear() and not restored by
early_ioremap_reset(). It at once eliminates the temporary (and configuration,
namely NR_CPUS, dependent) unavailability of early fixed mappings during the
time the fixmap area page tables get constructed.

Finally, also replace the hard coded calculation of the initial table space
needed for the fixmap area with a proper one, allowing kernels configured for
large CPU counts to actually boot.

Based-on: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16 13:47:04 +01:00
..
dump_pagetables.c x86: another user of PTE_FLAGS_MASK 2008-08-20 12:38:41 +02:00
extable.c
fault.c x86: avoid theoretical vmalloc fault loop 2009-01-12 19:24:21 +01:00
gup.c x86: two trivial sparse annotations 2008-10-29 08:02:28 +01:00
highmem_32.c Export kmap_atomic_pfn for DRM-GEM. 2008-10-18 07:10:12 +10:00
hugetlbpage.c x86: add hugepagesz option on 64-bit 2008-07-24 10:47:19 -07:00
init_32.c x86: fix assumed to be contiguous leaf page tables for kmap_atomic region (take 2) 2009-01-16 13:47:04 +01:00
init_64.c resource: allow MMIO exclusivity for device drivers 2009-01-07 11:12:32 -08:00
iomap_32.c x86: add iomap_atomic*()/iounmap_atomic() on 32-bit using fixmaps 2008-10-31 10:12:38 +01:00
ioremap.c x86: fix assumed to be contiguous leaf page tables for kmap_atomic region (take 2) 2009-01-16 13:47:04 +01:00
k8topology_64.c x86: k8 numa register active regions later 2009-01-06 13:21:21 +01:00
kmmio.c - fix mmioftrace + rcu merge interaction 2008-05-25 09:51:43 +02:00
Makefile Merge branches 'tracing/ftrace', 'tracing/fastboot', 'tracing/nmisafe' and 'tracing/urgent' into tracing/core 2008-11-08 09:34:35 +01:00
memtest.c x86: memtest fix use of reserve_early() 2008-10-22 17:08:06 +02:00
mmap.c
mmio-mod.c mmiotrace: remove left-over marker cruft 2008-10-14 10:37:17 +02:00
numa_32.c trivial: replace last usages of __FUNCTION__ in kernel 2009-01-07 15:48:54 -08:00
numa_64.c x86: prepare for cpumask iterators to only go to nr_cpu_ids 2008-12-16 17:40:58 -08:00
pageattr-test.c x86: make sure the CPA test code's use of _PAGE_UNUSED1 is obvious 2008-09-05 17:09:57 +02:00
pageattr.c x86: align DirectMap in /proc/meminfo 2008-11-06 15:27:37 +01:00
pat.c x86, pat: fix reserve_memtype() for legacy 1MB range 2009-01-14 20:14:45 +01:00
pf_in.c x86: fix mmiotrace 8-bit register decoding 2008-10-14 10:33:50 +02:00
pf_in.h
pgtable_32.c i386: vmalloc size fix 2008-08-21 10:13:21 +02:00
pgtable.c x86: pgd_{c,d}tor() cleanup 2008-09-06 19:47:09 +02:00
srat_32.c x86: don't call e820_regiter_active_regions if out of range on node 2008-08-14 11:35:52 +02:00
srat_64.c x86: prepare for cpumask iterators to only go to nr_cpu_ids 2008-12-16 17:40:58 -08:00
testmmiotrace.c x86 mmiotrace: implement mmiotrace_printk() 2008-10-14 10:37:11 +02:00