[pypy-commit] pypy default: Add a bad workaround that should hopefully fix the JIT

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r48082:f671d242b164
Date: 2011-10-16 15:09 +0200
http://bitbucket.org/pypy/pypy/changeset/f671d242b164/

Log:	Add a bad workaround that should hopefully fix the JIT in the
	presence of _continuations --- mostly by killing the performance of
	the JIT for any loop that involves _continuations.

diff --git a/pypy/module/_continuation/interp_continuation.py b/pypy/module/_continuation/interp_continuation.py
--- a/pypy/module/_continuation/interp_continuation.py
+++ b/pypy/module/_continuation/interp_continuation.py
@@ -28,6 +28,8 @@
     def descr_init(self, w_callable, __args__):
         if self.sthread is not None:
             raise geterror(self.space, "continulet already __init__ialized")
+        sthread = build_sthread(self.space)
+        workaround_disable_jit(sthread)
         #
         # hackish: build the frame "by hand", passing it the correct arguments
         space = self.space
@@ -41,7 +43,6 @@
         self.bottomframe = bottomframe
         #
         global_state.origin = self
-        sthread = build_sthread(self.space)
         self.sthread = sthread
         h = sthread.new(new_stacklet_callback)
         post_switch(sthread, h)
@@ -71,6 +72,7 @@
                 global_state.clear()
                 raise geterror(self.space, "continulet already finished")
         self.check_sthread()
+        workaround_disable_jit(self.sthread)
         #
         global_state.origin = self
         if to is None:
@@ -259,6 +261,16 @@
         sthread = ec.stacklet_thread = SThread(space, ec)
     return sthread
 
+def workaround_disable_jit(sthread):
+    # A bad workaround to kill the JIT anywhere in this thread.
+    # This forces all the frames.  It's a bad workaround because
+    # it takes O(depth) time, and it will cause some "abort:
+    # vable escape" in the JIT.  The goal is to prevent any frame
+    # from being still virtuals, because the JIT generates code
+    # to un-virtualizable them "on demand" by loading values based
+    # on FORCE_TOKEN, which is an address in the stack.
+    sthread.ec.force_all_frames()
+
 # ____________________________________________________________
 
 def permute(space, args_w):