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From 8aacb573cd2c4a2f8160d99ff100ad0aa5e7859d Mon Sep 17 00:00:00 2001
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From: Carl Love <cel@us.ibm.com>
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Date: Thu, 25 Jul 2019 10:24:16 -0400
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Subject: [PATCH] Only start the application if the perf events setup was
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successful
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Changes the order of starting the application and performance events.
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Given this change we have a new issue. The issue is the routine
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start_counting() calls fork, creating app_PID process.
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The parent then tries to setup the performance events, then if the
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performance events were setup correctly, app_PID is then told to start
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before exiting. If the performance counter setup fails, the app_PID is
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left running. The app_PID is never told to start the workload, which is
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correct but we don't record the fact that app_PID is running. The
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error path then fails to kill app_PID in routine main(), in file
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oprofile-git/pe_counting, at about lie 909 because the if statement
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if (startApp && app_started && (run_result != APP_ABNORMAL_END)) {
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is false because app_started is False.
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The fix, I believe, is to set app_started to True in the parent code if
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the fork was successful. With this fix, there is no orphan processes
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left after ocount exits.
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---
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pe_counting/ocount.cpp | 5 ++++-
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1 file changed, 4 insertions(+), 1 deletion(-)
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diff --git a/pe_counting/ocount.cpp b/pe_counting/ocount.cpp
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index 77177176..2470745d 100644
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--- a/pe_counting/ocount.cpp
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+++ b/pe_counting/ocount.cpp
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@@ -242,6 +242,10 @@ bool start_counting(void)
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// parent
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int startup;
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+ if ( app_PID != -1)
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+ // app_PID child process created successfully
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+ app_started = true;
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+
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if (startApp) {
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if (read(app_ready_pipe[0], &startup, sizeof(startup)) == -1) {
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perror("Internal error on app_ready_pipe");
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@@ -297,7 +301,6 @@ bool start_counting(void)
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perror("Internal error on start_app_pipe");
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return false;
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}
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- app_started = true;
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}
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return ret;
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--
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2.21.0
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