Blindly writing to is_lazy for no reason, when the written value is
identical to the old value, makes the cacheline dirty for no reason.
Avoid making such writes to prevent cache coherency traffic for no
reason.
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20210220231712.2475218-7-namit@vmware.com
__flush_tlb_all();
}
#endif
- this_cpu_write(cpu_tlbstate_shared.is_lazy, false);
+ if (was_lazy)
+ this_cpu_write(cpu_tlbstate_shared.is_lazy, false);
/*
* The membarrier system call requires a full memory barrier and