Merge pull request #50 from lsst/tickets/DM-43771

DM-43771: disable warping kernel caching and make sure we do PSF-evaluation caching.

python/lsst/drp/tasks/assemble_coadd.py

@@ -276,6 +276,7 @@ class AssembleCoaddConfig(
     def setDefaults(self):
         super().setDefaults()
         self.badMaskPlanes = ["NO_DATA", "BAD", "SAT", "EDGE"]
+        self.coaddPsf.cacheSize = 0
 
     def validate(self):
         super().validate()

python/lsst/drp/tasks/forcedPhotCoadd.py

@@ -320,6 +320,12 @@ def run(self, measCat, exposure, refCat, refWcs, exposureId=None):
                 Catalog of forced measurement results
                 (`lsst.afw.table.SourceCatalog`).
         """
+        # We want to cache repeated PSF evaluations at the same point coming
+        # from different measurement plugins.  We assume each algorithm tries
+        # to evaluate the PSF twice, which is more than enough since many don't
+        # evaluate it at all, and there's no *good* reason for any algorithm to
+        # evaluate it more than once.
+        exposure.psf.setCacheCapacity(2 * len(self.config.measurement.plugins.names))
         self.measurement.run(measCat, exposure, refCat, refWcs, exposureId=exposureId)
         if self.config.doApCorr:
             self.applyApCorr.run(catalog=measCat, apCorrMap=exposure.getInfo().getApCorrMap())