[LTP] [PATCH 1/2] read_all: Add worker timeout

[Li Wang]

Hi Richard,

On Tue, Jul 12, 2022 at 8:46 PM Richard Palethorpe <rpalethorpe@suse.com>
wrote:

> Kill and restart workers that take too long to read a file. The
> default being one second. A custom time can be set with the new -t
> option.
>
> This is to prevent a worker from blocking forever in a read. Currently
> when this happens the whole test times out and any remaining files in
> the worker's queue are not tested.
>
> As a side effect we can now also set the timeout very low to cause
> partial reads.
>

To restart workers which are blocked from reading files is a practical way.
My only concern is that restarted-worker is also slower reading on some
specific files so it will still be timed out again. Then the rest will fall
into
restart cycles. Here I'd suggest loosening the worker_timeout to 3000 ms
to accommodate systems of different IO speeds.

Though each worker at most takes 3secs, the max time would not
be overdue 45s (3 sec * max_works), unless tested sequentially
in the worst case. So bumping up max_runtime maybe also helpful.

Anyway, I'd be happy to apply your patch first to see how things going.
Reviewed-by: Li Wang <liwang@redhat.com>

--- a/testcases/kernel/fs/read_all/read_all.c
+++ b/testcases/kernel/fs/read_all/read_all.c
@@ -64,7 +64,7 @@ struct queue {
 struct worker {
        pid_t pid;
        struct queue *q;
-       int last_seen;
+       unsigned long long last_seen;
 };

 enum dent_action {
@@ -86,7 +86,7 @@ static long max_workers = 15;
 static struct worker *workers;
 static char *drop_privs;
 static char *str_worker_timeout;
-static int worker_timeout = 1000;
+static int worker_timeout = 3000;

 static char *blacklist[] = {
        NULL, /* reserved for -e parameter */
@@ -552,5 +552,6 @@ static struct tst_test test = {
        .cleanup = cleanup,
        .test_all = run,
        .forks_child = 1,
+       .max_runtime = 60,
 };


-- 
Regards,
Li Wang
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