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First step in pushing down the page_table_lock. init_mm.page_table_lock has been used throughout the architectures (usually for ioremap): not to serialize kernel address space allocation (that's usually vmlist_lock), but because pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it. Reverse that: don't lock or unlock init_mm.page_table_lock in any of the architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take and drop it when allocating a new one, to check lest a racing task already did. Similarly no page_table_lock in vmalloc's map_vm_area. Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle user mms, which are converted only by a later patch, for now they have to lock differently according to whether or not it's init_mm. If sources get muddled, there's a danger that an arch source taking init_mm.page_table_lock will be mixed with common source also taking it (or neither take it). So break the rules and make another change, which should break the build for such a mismatch: remove the redundant mm arg from pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13). Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64 used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64 map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free took page_table_lock for no good reason. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> |
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| .. | ||
| align.c | ||
| asm-offsets.c | ||
| bitops.c | ||
| cpu_setup_6xx.S | ||
| cpu_setup_power4.S | ||
| cputable.c | ||
| dma-mapping.c | ||
| entry.S | ||
| fpu.S | ||
| head_4xx.S | ||
| head_8xx.S | ||
| head_44x.S | ||
| head_booke.h | ||
| head_fsl_booke.S | ||
| head.S | ||
| idle_6xx.S | ||
| idle_power4.S | ||
| idle.c | ||
| irq.c | ||
| l2cr.S | ||
| machine_kexec.c | ||
| Makefile | ||
| misc.S | ||
| module.c | ||
| pci.c | ||
| perfmon_fsl_booke.c | ||
| perfmon.c | ||
| ppc_htab.c | ||
| ppc_ksyms.c | ||
| ppc-stub.c | ||
| process.c | ||
| ptrace.c | ||
| relocate_kernel.S | ||
| semaphore.c | ||
| setup.c | ||
| signal.c | ||
| smp-tbsync.c | ||
| smp.c | ||
| softemu8xx.c | ||
| swsusp.S | ||
| syscalls.c | ||
| temp.c | ||
| time.c | ||
| traps.c | ||
| vecemu.c | ||
| vector.S | ||
| vmlinux.lds.S | ||