delayacct: track delays from IRQ/SOFTIRQ

Delay accounting does not track the delay of IRQ/SOFTIRQ.  While
IRQ/SOFTIRQ could have obvious impact on some workloads productivity, such
as when workloads are running on system which is busy handling network
IRQ/SOFTIRQ.

Get the delay of IRQ/SOFTIRQ could help users to reduce such delay.  Such
as setting interrupt affinity or task affinity, using kernel thread for
NAPI etc.  This is inspired by "sched/psi: Add PSI_IRQ to track
IRQ/SOFTIRQ pressure"[1].  Also fix some code indent problems of older
code.

And update tools/accounting/getdelays.c:
    / # ./getdelays -p 156 -di
    print delayacct stats ON
    printing IO accounting
    PID     156

    CPU             count     real total  virtual total    delay total  delay average
                       15       15836008       16218149      275700790         18.380ms
    IO              count    delay total  delay average
                        0              0          0.000ms
    SWAP            count    delay total  delay average
                        0              0          0.000ms
    RECLAIM         count    delay total  delay average
                        0              0          0.000ms
    THRASHING       count    delay total  delay average
                        0              0          0.000ms
    COMPACT         count    delay total  delay average
                        0              0          0.000ms
    WPCOPY          count    delay total  delay average
                       36        7586118          0.211ms
    IRQ             count    delay total  delay average
                       42         929161          0.022ms

[1] commit 52b1364ba0b1("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure")

Link: https://lkml.kernel.org/r/202304081728353557233@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Cc: Jiang Xuexin <jiang.xuexin@zte.com.cn>
Cc: wangyong <wang.yong12@zte.com.cn>
Cc: junhua huang <huang.junhua@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yang Yang
2023-04-08 17:28:35 +08:00
committed by Andrew Morton
parent 29692fc92c
commit a3b2aeac9d
6 changed files with 58 additions and 15 deletions

View File

@@ -48,10 +48,13 @@ struct task_delay_info {
u64 wpcopy_start;
u64 wpcopy_delay; /* wait for write-protect copy */
u64 irq_delay; /* wait for IRQ/SOFTIRQ */
u32 freepages_count; /* total count of memory reclaim */
u32 thrashing_count; /* total count of thrash waits */
u32 compact_count; /* total count of memory compact */
u32 wpcopy_count; /* total count of write-protect copy */
u32 irq_count; /* total count of IRQ/SOFTIRQ */
};
#endif
@@ -81,6 +84,7 @@ extern void __delayacct_compact_start(void);
extern void __delayacct_compact_end(void);
extern void __delayacct_wpcopy_start(void);
extern void __delayacct_wpcopy_end(void);
extern void __delayacct_irq(struct task_struct *task, u32 delta);
static inline void delayacct_tsk_init(struct task_struct *tsk)
{
@@ -215,6 +219,15 @@ static inline void delayacct_wpcopy_end(void)
__delayacct_wpcopy_end();
}
static inline void delayacct_irq(struct task_struct *task, u32 delta)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (task->delays)
__delayacct_irq(task, delta);
}
#else
static inline void delayacct_init(void)
{}
@@ -253,6 +266,8 @@ static inline void delayacct_wpcopy_start(void)
{}
static inline void delayacct_wpcopy_end(void)
{}
static inline void delayacct_irq(struct task_struct *task, u32 delta)
{}
#endif /* CONFIG_TASK_DELAY_ACCT */