[IA64] Avoid unnecessary TLB flushes when allocating memory

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Improve performance of memory allocations on ia64 by avoiding a global TLB
purge to purge a single page from the file cache. This happens whenever we
evict a page from the buffer cache to make room for some other allocation.

Test case: Run 'find /usr -type f | xargs cat > /dev/null' in the
background to fill the buffer cache, then run something that uses memory,
e.g. 'gmake -j50 install'. Instrumentation showed that the number of
global TLB purges went from a few millions down to about 170 over a 12
hours run of the above.

The performance impact is particularly noticeable under virtualization,
because a virtual TLB is generally both larger and slower to purge than
a physical one.

Signed-off-by: Christophe de Dinechin <ddd@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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de Dinechin, Christophe (Integrity VM) 2007-12-13 15:03:07 +00:00 • committed by Tony Luck

parent 3cdc7fc7fd

commit aec103bfa6

1 changed files with 15 additions and 3 deletions

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arch/ia64/mm/tlb.c

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