Messages in this thread Patch in this message | | | Date | Wed, 18 Jun 2008 12:40:25 +0100 | From | "Jan Beulich" <> | Subject | [PATCH] i386: fix vmalloc_sync_all() for Xen |
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Since the fourth PDPT entry cannot be shared under Xen, vmalloc_sync_all() must iterate over pmd-s rather than pgd-s here. Luckily, the code isn't used for native PAE (SHARED_KERNEL_PMD is 1) and the change is benign to non-PAE.
Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- arch/x86/mm/fault.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-)
--- linux-2.6.26-rc6/arch/x86/mm/fault.c 2008-06-18 09:56:16.000000000 +0200 +++ 2.6.26-rc6-i386-xen-vmalloc_sync_all/arch/x86/mm/fault.c 2008-06-06 08:51:52.000000000 +0200 @@ -921,32 +921,43 @@ void vmalloc_sync_all(void) * start are only improving performance (without affecting correctness * if undone). */ - static DECLARE_BITMAP(insync, PTRS_PER_PGD); +#define sync_index(a) ((a) >> PMD_SHIFT) + static DECLARE_BITMAP(insync, PTRS_PER_PGD*PTRS_PER_PMD); static unsigned long start = TASK_SIZE; unsigned long address; if (SHARED_KERNEL_PMD) return; - BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK); - for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) { - if (!test_bit(pgd_index(address), insync)) { + BUILD_BUG_ON(TASK_SIZE & ~PMD_MASK); + for (address = start; address >= TASK_SIZE; address += PMD_SIZE) { + if (!test_bit(sync_index(address), insync)) { unsigned long flags; struct page *page; spin_lock_irqsave(&pgd_lock, flags); + if (unlikely(list_empty(&pgd_list))) { + spin_unlock_irqrestore(&pgd_lock, flags); + return; + } list_for_each_entry(page, &pgd_list, lru) { if (!vmalloc_sync_one(page_address(page), - address)) + address)) { + BUG_ON(list_first_entry(&pgd_list, + struct page, + lru) != page); + page = NULL; break; + } } spin_unlock_irqrestore(&pgd_lock, flags); - if (!page) - set_bit(pgd_index(address), insync); + if (page) + set_bit(sync_index(address), insync); } - if (address == start && test_bit(pgd_index(address), insync)) - start = address + PGDIR_SIZE; + if (address == start && test_bit(sync_index(address), insync)) + start = address + PMD_SIZE; } +#undef sync_index #else /* CONFIG_X86_64 */ /* * Note that races in the updates of insync and start aren't
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