-conservative option to split ironclad from slight risk but faster

[derekbruening]

From bruen...@google.com on December 07, 2011 13:15:57

as part of issue #460 I'm considering a -conservative option that's off by
default, letting me do technically risky but 99.9% safe stuff and improve
performance.

things like: read retaddr off stack an entrance to hooked callee w/o
try/except. read args off stack as well. remember this is on entrance to
standard allocation routines. extremely unlikely to have a bad stack
pointer there: requires hand-rolled bizarre code.

another: assume module won't be racily unloaded while code inside it
continues to execute: allowing me to pass data structs around that might be
deleted on racy unload and avoid table lookups at hook time.

Original issue: http://code.google.com/p/drmemory/issues/detail?id=708

[derekbruening]

From bruen...@google.com on December 08, 2011 10:12:40

-leaks_only -no_count_leaks
0.00user 0.01system 0:27.97elapsed 0%CPU (0avgtext+0avgdata 234240maxresident)k
0.00user 0.00system 0:27.53elapsed 0%CPU (0avgtext+0avgdata 234240maxresident)k
0.00user 0.00system 0:27.95elapsed 0%CPU (0avgtext+0avgdata 233984maxresident)k
-conservative -leaks_only -no_count_leaks
0.00user 0.00system 0:36.41elapsed 0%CPU (0avgtext+0avgdata 234496maxresident)k
0.00user 0.00system 0:38.34elapsed 0%CPU (0avgtext+0avgdata 234496maxresident)k
0.00user 0.00system 0:36.91elapsed 0%CPU (0avgtext+0avgdata 234240maxresident)k

[derekbruening]

From derek.br...@gmail.com on December 08, 2011 12:54:30

This issue was closed by revision r665 .

Status: Fixed