docs/specs/ppc-spapr-numa.rst

11 Associativity and ibm,associativity property
12 --------------------------------------------
18 The format of the ibm,associativity property varies with the value of
19 bit 0 of byte 5 of the ibm,architecture-vec-5 property. The format with
21 with the value of one, makes ibm,associativity property represent the
28     Mem M1 ---- Proc P1    |
29     -----------------      | Socket S1  ---|
32     Mem M2 ---- Proc P2    |               |
33     -----------------      | Socket S2  ---|
36 The ibm,associativity property for the processors would be:
41 Each allocable resource has an ibm,associativity property. The LOPAPR
42 specification allows multiple lists to be present in this property,
46 Relative Performance Distance and ibm,associativity-reference-points
47 --------------------------------------------------------------------
49 The ibm,associativity-reference-points property is an array that is used
54 of the ibm,architecture-vec-5 property. The format with bit 0 equal to zero
56 ibm,associativity-reference-points represents an 1 based ordinal index (i.e.
57 the first element is 1) of the ibm,associativity array. The first
69 * ibm,associativity-reference-points = {0x3, 0x2, 0x1}
72 ibm,associativity array, the second level is the second element and
81   * ibm,associativity-reference-points = {0x3, 0x2, 0x1}
97 Changing the ibm,associativity-reference-points array changes the performance
103   * ibm,associativity-reference-points = {0x2}
123   * ibm,associativity-reference-points = {0x1}
144 provides a common-performance hierarchy,  and the ibm,associativity-reference-points
145 array that tells which level of associativity is considered to be relevant
167 * ibm,associativity-reference-points is set to {0x4, 0x3, 0x2, 0x1}, allowing
170 * ibm,max-associativity-domains supports multiple associativity domains in all
175 These changes are only effective for pseries-5.2 and newer machines that are
189 --------------------------------------------
206 have to accept that a large array of values will be translated to the same
241 --------------------------------------
243 LOPAPR allows more than one associativity array (or 'string') per allocated
329 Note that this is not what the user wanted - the desired distance between
340 ---------------------------------
349   any A-B pair where the distance back and forth is asymmetric. For example, the
360 * 'non-transitive' topologies will be poorly translated to the guest. This is the
392 the default ibm,associativity-reference-points being used in the pseries
395 ibm,associativity-reference-points = {0x4, 0x4, 0x2}