From 8a67a20bf257ca378d6e5588fbe4382966395ac8 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 25 Nov 2020 13:00:04 -0800 Subject: [PATCH] torture: Throttle VERBOSE_TOROUT_*() output This commit adds kernel boot parameters torture.verbose_sleep_frequency and torture.verbose_sleep_duration, which allow VERBOSE_TOROUT_*() output to be throttled with periodic sleeps on large systems. Signed-off-by: Paul E. McKenney --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++ include/linux/torture.h | 15 +++++++++++++-- kernel/torture.c | 20 ++++++++++++++++++++ 3 files changed, 41 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3244f9e..18f3aa7 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5337,6 +5337,14 @@ are running concurrently, especially on systems with rotating-rust storage. + torture.verbose_sleep_frequency= [KNL] + Specifies how many verbose printk()s should be + emitted between each sleep. The default of zero + disables verbose-printk() sleeping. + + torture.verbose_sleep_duration= [KNL] + Duration of each verbose-printk() sleep in jiffies. + tp720= [HW,PS2] tpm_suspend_pcr=[HW,TPM] diff --git a/include/linux/torture.h b/include/linux/torture.h index 32941f8..d62d13c 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -32,9 +32,20 @@ #define TOROUT_STRING(s) \ pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s) #define VERBOSE_TOROUT_STRING(s) \ - do { if (verbose) pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); } while (0) +do { \ + if (verbose) { \ + verbose_torout_sleep(); \ + pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); \ + } \ +} while (0) #define VERBOSE_TOROUT_ERRSTRING(s) \ - do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0) +do { \ + if (verbose) { \ + verbose_torout_sleep(); \ + pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); \ + } \ +} while (0) +void verbose_torout_sleep(void); /* Definitions for online/offline exerciser. */ typedef void torture_ofl_func(void); diff --git a/kernel/torture.c b/kernel/torture.c index 7ad5c96..93eeeb2b 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -48,6 +48,12 @@ module_param(disable_onoff_at_boot, bool, 0444); static bool ftrace_dump_at_shutdown; module_param(ftrace_dump_at_shutdown, bool, 0444); +static int verbose_sleep_frequency; +module_param(verbose_sleep_frequency, int, 0444); + +static int verbose_sleep_duration = 1; +module_param(verbose_sleep_duration, int, 0444); + static char *torture_type; static int verbose; @@ -58,6 +64,20 @@ static int verbose; static int fullstop = FULLSTOP_RMMOD; static DEFINE_MUTEX(fullstop_mutex); +static atomic_t verbose_sleep_counter; + +/* + * Sleep if needed from VERBOSE_TOROUT*(). + */ +void verbose_torout_sleep(void) +{ + if (verbose_sleep_frequency > 0 && + verbose_sleep_duration > 0 && + !(atomic_inc_return(&verbose_sleep_counter) % verbose_sleep_frequency)) + schedule_timeout_uninterruptible(verbose_sleep_duration); +} +EXPORT_SYMBOL_GPL(verbose_torout_sleep); + /* * Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit * nanosecond random fuzz. This function and its friends desynchronize -- 2.7.4