config: Initialize and check cpt_starttick

The previous changeset (9816) that fixes the use of max ticks introduced the
variable cpt_starttick, which is used for setting the relative max tick.
Unfortunately, with checkpointing at an instruction count or with simpoints,
the checkpoint tick is not stored conveniently, so to ensure that cpt_starttick
is initialized, set it to 0. Also, if using --rel-max-tick, check the use of
instruction counts or simpoints to warn the user that the max tick setting does
not include the checkpoint ticks.

1 files changed, 6 insertions, 0 deletions

diff --git a/configs/common/Simulation.py b/configs/common/Simulation.py
index f88888dc4..c5d7aee40 100644
--- a/configs/common/Simulation.py
+++ b/configs/common/Simulation.py
@@ -126,6 +126,7 @@ def findCptDir(options, cptdir, testsys):
     if not isdir(cptdir):
         fatal("checkpoint dir %s does not exist!", cptdir)
 
+    cpt_starttick = 0
     if options.at_instruction or options.simpoint:
         inst = options.checkpoint_restore
         if options.simpoint:
@@ -430,6 +431,11 @@ def run(options, root, testsys, cpu_class):
             # NOTE: this may need to be updated if checkpoints ever store
             # the ticks per simulated second
             maxtick_from_rel += cpt_starttick
+            if options.at_instruction or options.simpoint:
+                warn("Relative max tick specified with --at-instruction or" \
+                     " --simpoint\n      These options don't specify the " \
+                     "checkpoint start tick, so assuming\n      you mean " \
+                     "absolute max tick")
         explicit_maxticks += 1
     if options.maxtime:
         maxtick_from_maxtime = m5.ticks.fromSeconds(options.maxtime)