From a8c024cd9b9683d25ae1f459525dd2c6bec75e79 Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Mon, 19 Mar 2018 14:35:54 -0400 Subject: sched/debug: Fix per-task line continuation for console output When the SEQ_printf() macro prints to the console, it runs a simple printk() without KERN_CONT "continued" line printing. The result of this is oddly wrapped task info, for example: % echo t > /proc/sysrq-trigger % dmesg ... runnable tasks: ... [ 29.608611] I [ 29.608613] rcu_sched 8 3252.013846 4087 120 [ 29.608614] 0.000000 29.090111 0.000000 [ 29.608615] 0 0 [ 29.608616] / Modify SEQ_printf to use pr_cont() for expected one-line results: % echo t > /proc/sysrq-trigger % dmesg ... runnable tasks: ... [ 106.716329] S cpuhp/5 37 2006.315026 14 120 0.000000 0.496893 0.000000 0 0 / Signed-off-by: Joe Lawrence Acked-by: Peter Zijlstra Cc: Linus Torvalds Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1521484555-8620-2-git-send-email-joe.lawrence@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 1ca0130ed4f9..50026aa2d81e 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -32,7 +32,7 @@ static DEFINE_SPINLOCK(sched_debug_lock); if (m) \ seq_printf(m, x); \ else \ - printk(x); \ + pr_cont(x); \ } while (0) /* -- cgit v1.2.3 From e9ca267096674eadd1fd479279bcb58df1486049 Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Mon, 19 Mar 2018 14:35:55 -0400 Subject: sched/debug: Adjust newlines for better alignment Scheduler debug stats include newlines that display out of alignment when prefixed by timestamps. For example, the dmesg utility: % echo t > /proc/sysrq-trigger % dmesg ... [ 83.124251] runnable tasks: S task PID tree-key switches prio wait-time sum-exec sum-sleep ----------------------------------------------------------------------------------------------------------- At the same time, some syslog utilities (like rsyslog by default) don't like the additional newlines control characters, saving lines like this to /var/log/messages: Mar 16 16:02:29 localhost kernel: #012runnable tasks:#012 S task PID tree-key ... ^^^^ ^^^^ Clean these up by moving newline characters to their own SEQ_printf invocation. This leaves the /proc/sched_debug unchanged, but brings the entire output into alignment when prefixed: % echo t > /proc/sysrq-trigger % dmesg ... [ 62.410368] runnable tasks: [ 62.410368] S task PID tree-key switches prio wait-time sum-exec sum-sleep [ 62.410369] ----------------------------------------------------------------------------------------------------------- [ 62.410369] I kworker/u12:0 5 1932.215593 332 120 0.000000 3.621252 0.000000 0 0 / and no escaped control characters from rsyslog in /var/log/messages: Mar 16 16:15:06 localhost kernel: runnable tasks: Mar 16 16:15:06 localhost kernel: S task PID tree-key ... Signed-off-by: Joe Lawrence Acked-by: Peter Zijlstra Cc: Linus Torvalds Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1521484555-8620-3-git-send-email-joe.lawrence@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/debug.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 50026aa2d81e..72c401b3b15c 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -501,12 +501,12 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) { struct task_struct *g, *p; - SEQ_printf(m, - "\nrunnable tasks:\n" - " S task PID tree-key switches prio" - " wait-time sum-exec sum-sleep\n" - "-------------------------------------------------------" - "----------------------------------------------------\n"); + SEQ_printf(m, "\n"); + SEQ_printf(m, "runnable tasks:\n"); + SEQ_printf(m, " S task PID tree-key switches prio" + " wait-time sum-exec sum-sleep\n"); + SEQ_printf(m, "-------------------------------------------------------" + "----------------------------------------------------\n"); rcu_read_lock(); for_each_process_thread(g, p) { @@ -527,9 +527,11 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) unsigned long flags; #ifdef CONFIG_FAIR_GROUP_SCHED - SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg)); + SEQ_printf(m, "\n"); + SEQ_printf(m, "cfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg)); #else - SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu); + SEQ_printf(m, "\n"); + SEQ_printf(m, "cfs_rq[%d]:\n", cpu); #endif SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock", SPLIT_NS(cfs_rq->exec_clock)); @@ -595,9 +597,11 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq) { #ifdef CONFIG_RT_GROUP_SCHED - SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg)); + SEQ_printf(m, "\n"); + SEQ_printf(m, "rt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg)); #else - SEQ_printf(m, "\nrt_rq[%d]:\n", cpu); + SEQ_printf(m, "\n"); + SEQ_printf(m, "rt_rq[%d]:\n", cpu); #endif #define P(x) \ @@ -624,7 +628,8 @@ void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq) { struct dl_bw *dl_bw; - SEQ_printf(m, "\ndl_rq[%d]:\n", cpu); + SEQ_printf(m, "\n"); + SEQ_printf(m, "dl_rq[%d]:\n", cpu); #define PU(x) \ SEQ_printf(m, " .%-30s: %lu\n", #x, (unsigned long)(dl_rq->x)) -- cgit v1.2.3