GH-93533: Shrink the LOAD_ATTR
caches
#103014
Closed
+330
−265
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This adds a fixed array of cached methods to the
PyTypeObject
struct. This approach saves memory if there are ~23x moreLOAD_ATTR
sites than there are types.A size of 16 was chosen because:
LOAD_ATTR
hit rate onpyperformance
, with 32.5% of specialization failures due to a too-small cache.LOAD_ATTR
hit rate onpyperformance
, with 8.7% of specialization failures due to a too-small cache.LOAD_ATTR
hit rate onpyperformance
, with 3.3% of specialization failures due to a too-small cache.A flexible buffer was also considered, but that was 1% slower, likely due to the additional indirection and management of the buffer.
LOAD_ATTR
is too large. #93533