tlb - TLB size and latency benchmark

       Carl Staelin and Larry McVoy

       Comments, suggestions, and bug reports are always welcome.

(c)2000 Carl Staelin and Larry McVoy                 $Date$                                               TLB(8)

tlb is an experimental benchmark, but it seems to work well on most systems.  However, if a processor has
       a TLB hierarchy tlb only finds the top level TLB.

tlb  tries  to determine the size, in pages, of the TLB.  The largest amount of memory it will examine is
       len bytes.

       tlb compares the memory latency for two different pointer chains.  The two chains occupy the same  amount
       of  cache space, but they stress the memory subsystem differently.  The first chain accesses one word per
       page, while the second chain randomly jumps through all the lines on a page before jumping  to  the  next
       page.   When  all of the pointers reside in the cache (which is the usual case), and all of the pages for
       the first chain reside in the TLB, then the average memory latencies should be identical.  Assuming there
       is a fixed size TLB, then at some point the number of pages accessed by the first  page  will  be  larger
       than  the  TLB.   At  this point the average latency for each memory access for the first chain will be a
       cache hit plus some fraction of a TLB miss.

       Once the TLB boundary is located tlb reports the TLB miss latency as the TLB latency for  twice  as  many
       pages as the TLB can hold.

       tlb - TLB size and latency benchmark

lmbench(8), line(8), cache(8), par_mem(8).

tlb [ -L<linesize> ] [ -M<len> ] [ -W<warmups> ] [ -N<repetitions> ]