Re: _clear_page semantics
From: Ralf Baechle <hidden>
Date: 2001-01-10 15:45:44
On Wed, Jan 10, 2001 at 09:08:08AM +0100, Carsten Langgaard wrote:
You are absolutely right, it is implementation dependent. I just tend to use the mips32 implementation for my R4000s as well, and here as Ralf mention it is performance improving. Actually we have included a CPU option flag (MIPS_CPU_CACHE_CDEX), what tells us if the CPU has the Create_Dirty_Exclusive CACHE operation available. So we should probably use it, now it is here :-)
Homework for somebody with some time at his hands - we have a large number of unrolled loops for all sorts of cache variations in r4xx0.c. Benchmark if they actually improve performance. I wouldn't wonder if due to a large number of pipeline stalls in one of those routines the whole unrolling business doesn't buy us anything. Ralf