The torture_shutdown_init() function spawns a shutdown kthread in a manner very similar to that implemented by ref_scale_shutdown(). This commit therefore re-implements ref_scale_shutdown in terms of torture_shutdown_init().
The initial draft of this patch was generated by version 2.1.16 of the Claude AI/LLM, but trained and configured for use by my employer, and prompted to refer to Linux-kernel source code. This initial draft failed to provide a forward reference to ref_scale_cleanup(), passed zero to torture_shutdown_init() for an unwelcome insta-shutdown, and failed to pass the kvm.sh --duration argument in as a refscale module parameter. On the other hand, it did catch the need to NULL main_task on the post-test self-shutdown code path, which I might well have forgotten to do. This version of the patch fixes those problems, and in fact very little of the initial draft remains. Signed-off-by: Paul E. McKenney <[email protected]> [outline more of development process] Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/refscale.c | 51 +++++-------------- .../configs/refscale/ver_functions.sh | 2 +- 2 files changed, 15 insertions(+), 38 deletions(-) diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index c158b6a947cde..a2d9d75d88a10 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -92,15 +92,9 @@ torture_param(int, nreaders, -1, "Number of readers, -1 for 75% of CPUs."); torture_param(int, nruns, 30, "Number of experiments to run."); // Reader delay in nanoseconds, 0 for no delay. torture_param(int, readdelay, 0, "Read-side delay in nanoseconds."); - -#ifdef MODULE -# define REFSCALE_SHUTDOWN 0 -#else -# define REFSCALE_SHUTDOWN 1 -#endif - -torture_param(bool, shutdown, REFSCALE_SHUTDOWN, - "Shutdown at end of scalability tests."); +// Maximum shutdown delay in seconds, or zero for no shutdown. +torture_param(int, shutdown_secs, !IS_MODULE(CONFIG_REPRO_TEST) * 300, + "Shutdown at end of scalability tests or at specified timeout (s)."); struct reader_task { struct task_struct *task; @@ -109,12 +103,8 @@ struct reader_task { u64 last_duration_ns; }; -static struct task_struct *shutdown_task; -static wait_queue_head_t shutdown_wq; - static struct task_struct *main_task; static wait_queue_head_t main_wq; -static int shutdown_start; static struct reader_task *reader_tasks; @@ -1357,6 +1347,8 @@ static u64 process_durations(int n) return sum; } +static void ref_scale_cleanup(void); + // The main_func is the main orchestrator, it performs a bunch of // experiments. For every experiment, it orders all the readers // involved to start and waits for them to finish the experiment. It @@ -1443,9 +1435,10 @@ static int main_func(void *arg) oom_exit: // This will shutdown everything including us. - if (shutdown) { - shutdown_start = 1; - wake_up(&shutdown_wq); + if (shutdown_secs) { + main_task = NULL; // Avoid self-kill deadlock. + ref_scale_cleanup(); + kernel_power_off(); } // Wait for torture to stop us @@ -1463,8 +1456,8 @@ static void ref_scale_print_module_parms(const struct ref_scale_ops *cur_ops, const char *tag) { pr_alert("%s" SCALE_FLAG - "--- %s: verbose=%d verbose_batched=%d shutdown=%d holdoff=%d lookup_instances=%ld loops=%d nreaders=%d nruns=%d readdelay=%d\n", scale_type, tag, - verbose, verbose_batched, shutdown, holdoff, lookup_instances, loops, nreaders, nruns, readdelay); + "--- %s: verbose=%d verbose_batched=%d shutdown_secs=%d holdoff=%d lookup_instances=%ld loops=%d nreaders=%d nruns=%d readdelay=%d\n", scale_type, tag, + verbose, verbose_batched, shutdown_secs, holdoff, lookup_instances, loops, nreaders, nruns, readdelay); } static void @@ -1497,19 +1490,6 @@ ref_scale_cleanup(void) torture_cleanup_end(); } -// Shutdown kthread. Just waits to be awakened, then shuts down system. -static int -ref_scale_shutdown(void *arg) -{ - wait_event_idle(shutdown_wq, shutdown_start); - - smp_mb(); // Wake before output. - ref_scale_cleanup(); - kernel_power_off(); - - return -EINVAL; -} - static int __init ref_scale_init(void) { @@ -1553,13 +1533,10 @@ ref_scale_init(void) ref_scale_print_module_parms(cur_ops, "Start of test"); // Shutdown task - if (shutdown) { - init_waitqueue_head(&shutdown_wq); - firsterr = torture_create_kthread(ref_scale_shutdown, NULL, - shutdown_task); + if (shutdown_secs) { + firsterr = torture_shutdown_init(shutdown_secs, ref_scale_cleanup); if (torture_init_error(firsterr)) goto unwind; - schedule_timeout_uninterruptible(1); } // Reader tasks (default to ~75% of online CPUs). @@ -1604,7 +1581,7 @@ ref_scale_init(void) unwind: torture_init_end(); ref_scale_cleanup(); - if (shutdown) { + if (shutdown_secs) { WARN_ON(!IS_MODULE(CONFIG_RCU_REF_SCALE_TEST)); kernel_power_off(); } diff --git a/tools/testing/selftests/rcutorture/configs/refscale/ver_functions.sh b/tools/testing/selftests/rcutorture/configs/refscale/ver_functions.sh index 7484656276012..219fac070af28 100644 --- a/tools/testing/selftests/rcutorture/configs/refscale/ver_functions.sh +++ b/tools/testing/selftests/rcutorture/configs/refscale/ver_functions.sh @@ -11,7 +11,7 @@ # # Adds per-version torture-module parameters to kernels supporting them. per_version_boot_params () { - echo refscale.shutdown=1 \ + echo refscale.shutdown_secs=$3 \ refscale.verbose=0 \ $1 } -- 2.40.1
