98 lines
3.0 KiB
Diff
98 lines
3.0 KiB
Diff
From c25a24cc237721c51034f4425183f73e97cdccc1 Mon Sep 17 00:00:00 2001
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From: Tom de Vries <tdevries@suse.de>
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Date: Mon, 6 Feb 2023 12:52:50 +0100
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Subject: [PATCH 06/11] [gdb/testsuite] Fix gdb.threads/schedlock.exp on fast
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cpu
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Occasionally, I run into:
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...
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(gdb) PASS: gdb.threads/schedlock.exp: schedlock=on: cmd=continue: \
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set scheduler-locking on
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continue^M
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Continuing.^M
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PASS: gdb.threads/schedlock.exp: schedlock=on: cmd=continue: \
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continue (with lock)
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[Thread 0x7ffff746e700 (LWP 1339) exited]^M
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No unwaited-for children left.^M
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(gdb) Quit^M
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(gdb) FAIL: gdb.threads/schedlock.exp: schedlock=on: cmd=continue: \
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stop all threads (with lock) (timeout)
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...
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What happens is that this loop which is supposed to run "just short of forever":
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...
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/* Don't run forever. Run just short of it :) */
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while (*myp > 0)
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{
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/* schedlock.exp: main loop. */
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MAYBE_CALL_SOME_FUNCTION(); (*myp) ++;
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}
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...
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finishes after 0x7fffffff iterations (when a signed wrap occurs), which on my
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system takes only about 1.5 seconds.
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Fix this by:
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- changing the pointed-at type of myp from signed to unsigned, which makes the
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wrap defined behaviour (and which also make the loop run twice as long,
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which is already enough to make it impossible for me to reproduce the FAIL.
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But let's try to solve this more structurally).
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- changing the pointed-at type of myp from int to long long, making the wrap
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unlikely.
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- making sure the loop runs forever, by setting the loop condition to 1.
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- making sure the loop still contains different lines (as far as debug info is
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concerned) by incrementing a volatile counter in the loop.
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- making sure the program doesn't run forever in case of trouble, by adding an
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"alarm (30)".
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Tested on x86_64-linux.
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PR testsuite/30074
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Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30074
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---
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gdb/testsuite/gdb.threads/schedlock.c | 11 +++++++----
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1 file changed, 7 insertions(+), 4 deletions(-)
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diff --git a/gdb/testsuite/gdb.threads/schedlock.c b/gdb/testsuite/gdb.threads/schedlock.c
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index 7672140fdc8..9859885b1a3 100644
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--- a/gdb/testsuite/gdb.threads/schedlock.c
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+++ b/gdb/testsuite/gdb.threads/schedlock.c
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@@ -24,7 +24,7 @@ void *thread_function(void *arg); /* Pointer to function executed by each thread
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#define NUM 1
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-unsigned int args[NUM+1];
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+unsigned long long int args[NUM+1];
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int main() {
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int res;
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@@ -32,6 +32,8 @@ int main() {
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void *thread_result;
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long i;
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+ alarm (30);
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+
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for (i = 1; i <= NUM; i++)
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{
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args[i] = 1;
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@@ -72,13 +74,14 @@ volatile int call_function = 0;
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void *thread_function(void *arg) {
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int my_number = (long) arg;
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- int *myp = (int *) &args[my_number];
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+ unsigned long long int *myp = (unsigned long long int *) &args[my_number];
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+ volatile unsigned int cnt = 0;
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- /* Don't run forever. Run just short of it :) */
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- while (*myp > 0)
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+ while (1)
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{
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/* schedlock.exp: main loop. */
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MAYBE_CALL_SOME_FUNCTION(); (*myp) ++;
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+ cnt++;
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}
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pthread_exit(NULL);
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--
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2.35.3
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