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| author | Peter Keilty <peter.keilty@hp.com> | 2005-11-01 00:44:47 +0300 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-11-01 01:36:05 +0300 |
| commit | dcc17d1baef3721d1574e5b2f4f2d4607514bcff (patch) | |
| tree | 78b19a9b54f57aa010f50201e7639786b0e5f770 /include/asm-ia64/mmu_context.h | |
| parent | f2c84c0e84bfa637a7161eac10157cf3b05b4a73 (diff) | |
| download | linux-dcc17d1baef3721d1574e5b2f4f2d4607514bcff.tar.xz | |
[IA64] Use bitmaps for efficient context allocation/free
Corrects the very inefficent method of finding free context_ids in
get_mmu_context(). Instead of walking the task_list of all processes,
2 bitmaps are used to efficently store and lookup state, inuse and
needs flushing. The entire rid address space is now used before calling
wrap_mmu_context and global tlb flushing.
Special thanks to Ken and Rohit for their review and modifications in
using a bit flushmap.
Signed-off-by: Peter Keilty <peter.keilty@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'include/asm-ia64/mmu_context.h')
| -rw-r--r-- | include/asm-ia64/mmu_context.h | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h index 8d6e72f7b08e..8d9b30b5f7d4 100644 --- a/include/asm-ia64/mmu_context.h +++ b/include/asm-ia64/mmu_context.h @@ -32,13 +32,17 @@ struct ia64_ctx { spinlock_t lock; unsigned int next; /* next context number to use */ - unsigned int limit; /* next >= limit => must call wrap_mmu_context() */ - unsigned int max_ctx; /* max. context value supported by all CPUs */ + unsigned int limit; /* available free range */ + unsigned int max_ctx; /* max. context value supported by all CPUs */ + /* call wrap_mmu_context when next >= max */ + unsigned long *bitmap; /* bitmap size is max_ctx+1 */ + unsigned long *flushmap;/* pending rid to be flushed */ }; extern struct ia64_ctx ia64_ctx; DECLARE_PER_CPU(u8, ia64_need_tlb_flush); +extern void mmu_context_init (void); extern void wrap_mmu_context (struct mm_struct *mm); static inline void @@ -83,9 +87,16 @@ get_mmu_context (struct mm_struct *mm) context = mm->context; if (context == 0) { cpus_clear(mm->cpu_vm_mask); - if (ia64_ctx.next >= ia64_ctx.limit) - wrap_mmu_context(mm); + if (ia64_ctx.next >= ia64_ctx.limit) { + ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + if (ia64_ctx.next >= ia64_ctx.max_ctx) + wrap_mmu_context(mm); + } mm->context = context = ia64_ctx.next++; + __set_bit(context, ia64_ctx.bitmap); } } spin_unlock_irqrestore(&ia64_ctx.lock, flags); |