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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-05-25 09:45:26 +0200 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-06-13 15:58:22 +0200 |
commit | 64f31d5802af11fd87872b4bae07b35cf0acb358 (patch) | |
tree | 73f514c73762092fd6710efa6863a5a6124d86a3 /arch/s390/include/asm/mmu.h | |
parent | bitmap: bitmap_equal memcmp optimization (diff) | |
download | linux-64f31d5802af11fd87872b4bae07b35cf0acb358.tar.xz linux-64f31d5802af11fd87872b4bae07b35cf0acb358.zip |
s390/mm: simplify the TLB flushing code
ptep_flush_lazy and pmdp_flush_lazy use mm->context.attach_count to
decide between a lazy TLB flush vs an immediate TLB flush. The field
contains two 16-bit counters, the number of CPUs that have the mm
attached and can create TLB entries for it and the number of CPUs in
the middle of a page table update.
The __tlb_flush_asce, ptep_flush_direct and pmdp_flush_direct functions
use the attach counter and a mask check with mm_cpumask(mm) to decide
between a local flush local of the current CPU and a global flush.
For all these functions the decision between lazy vs immediate and
local vs global TLB flush can be based on CPU masks. There are two
masks: the mm->context.cpu_attach_mask with the CPUs that are actively
using the mm, and the mm_cpumask(mm) with the CPUs that have used the
mm since the last full flush. The decision between lazy vs immediate
flush is based on the mm->context.cpu_attach_mask, to decide between
local vs global flush the mm_cpumask(mm) is used.
With this patch all checks will use the CPU masks, the old counter
mm->context.attach_count with its two 16-bit values is turned into a
single counter mm->context.flush_count that keeps track of the number
of CPUs with incomplete page table updates. The sole user of this
counter is finish_arch_post_lock_switch() which waits for the end of
all page table updates.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/mmu.h')
-rw-r--r-- | arch/s390/include/asm/mmu.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h index 081b2ad99d73..18226437a832 100644 --- a/arch/s390/include/asm/mmu.h +++ b/arch/s390/include/asm/mmu.h @@ -6,7 +6,7 @@ typedef struct { cpumask_t cpu_attach_mask; - atomic_t attach_count; + atomic_t flush_count; unsigned int flush_mm; spinlock_t list_lock; struct list_head pgtable_list; |