Commit bdcd93ef authored Jul 31, 2020 by Guo Ren

csky: Add context tracking support



This patch support context tracking with no hz full.

Here is the test result with dynticks-testing (see tick_stop):

 cat /sys/kernel/debug/tracing/per_cpu/cpu0/trace
 tracer: nop

 entries-in-buffer/entries-written: 356/356   #P:1

                              _-----=> irqs-off
                             / _----=> need-resched
                            | / _---=> hardirq/softirq
                            || / _--=> preempt-depth
                            ||| /     delay
           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
              | |       |   ||||       |         |
...
          sleep-192   [000] d.h.   167.088270: hrtimer_expire_entry: hrtimer=(ptrval) function=tick_sched_timer now=166436355700
          sleep-192   [000] d.h.   167.092279: hrtimer_expire_entry: hrtimer=(ptrval) function=tick_sched_timer now=166440365700
         <idle>-0     [000] d.h2   167.096492: hrtimer_expire_entry: hrtimer=(ptrval) function=tick_sched_timer now=166444578400
         <idle>-0     [000] d..1   167.097876: tick_stop: success=1 dependency=NONE
                                               ^^^^^^^^^
         <idle>-0     [000] d.h1   168.818206: hrtimer_expire_entry: hrtimer=(ptrval) function=tick_sched_timer now=168166280900
   kworker/u2:0-7     [000] ....   168.821760: workqueue_execute_start: work struct (ptrval): function wb_workfn
   kworker/u2:0-7     [000] d.h1   168.824464: hrtimer_expire_entry: hrtimer=(ptrval) function=tick_sched_timer now=168172547100
    kworker/0:1-18    [000] ....   168.825053: workqueue_execute_start: work struct (ptrval): function vmstat_update
    kworker/0:1-18    [000] ....   168.825238: workqueue_execute_start: work struct (ptrval): function vmstat_shepherd
    kworker/0:1-18    [000] ....   168.825516: workqueue_execute_start: work struct (ptrval): function neigh_periodic_work
         <idle>-0     [000] d..1   168.826121: tick_stop: success=1 dependency=NONE
   kworker/u2:0-7     [000] ....   169.377327: workqueue_execute_start: work struct (ptrval): function flush_to_ldisc
         <idle>-0     [000] d..1   169.379832: tick_stop: success=1 dependency=NONE
   kworker/u2:0-7     [000] ....   169.607935: workqueue_execute_start: work struct (ptrval): function flush_to_ldisc
   kworker/u2:0-7     [000] d.h1   169.608148: hrtimer_expire_entry: hrtimer=(ptrval) function=tick_sched_timer now=168956235500
         <idle>-0     [000] d..1   169.608654: tick_stop: success=1 dependency=NONE

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Greentime Hu <greentime.hu@sifive.com>
Cc: Arnd Bergmann <arnd@arndb.de>

parent e6169c4b

arch/csky/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,8 @@ config CSKY
		select HAVE_ARCH_MMAP_RND_BITS
		select HAVE_ARCH_SECCOMP_FILTER
		select HAVE_COPY_THREAD_TLS
		select HAVE_CONTEXT_TRACKING
		select HAVE_VIRT_CPU_ACCOUNTING_GEN
		select HAVE_DEBUG_BUGVERBOSE
		select HAVE_DYNAMIC_FTRACE
		select HAVE_DYNAMIC_FTRACE_WITH_REGS

arch/csky/kernel/entry.S

+25 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,24 @@
		#endif
		.endm

		.macro context_tracking
		#ifdef CONFIG_CONTEXT_TRACKING
		mfcr a0, epsr
		btsti a0, 31
		bt 1f
		jbsr context_tracking_user_exit
		ldw a0, (sp, LSAVE_A0)
		ldw a1, (sp, LSAVE_A1)
		ldw a2, (sp, LSAVE_A2)
		ldw a3, (sp, LSAVE_A3)
		#if defined(__CSKYABIV1__)
		ldw r6, (sp, LSAVE_A4)
		ldw r7, (sp, LSAVE_A5)
		#endif
		1:
		#endif
		.endm

		.macro tlbop_begin name, val0, val1, val2
		ENTRY(csky_\name)
		mtcr a3, ss2
		@@ -103,6 +121,7 @@ ENTRY(csky_\name)
		.endm
		.macro tlbop_end is_write
		zero_fp
		context_tracking
		RD_MEH a2
		psrset ee, ie
		mov a0, sp
		@@ -128,6 +147,7 @@ tlbop_end 1
		ENTRY(csky_systemcall)
		SAVE_ALL TRAP0_SIZE
		zero_fp
		context_tracking
		psrset ee, ie

		lrw r9, __NR_syscalls
		@@ -237,6 +257,9 @@ ret_from_exception:
		and r10, r9
		cmpnei r10, 0
		bt exit_work
		#ifdef CONFIG_CONTEXT_TRACKING
		jbsr context_tracking_user_enter
		#endif
		1:
		#ifdef CONFIG_PREEMPTION
		mov r9, sp
		@@ -277,6 +300,7 @@ work_resched:
		ENTRY(csky_trap)
		SAVE_ALL 0
		zero_fp
		context_tracking
		psrset ee
		mov a0, sp /* Push Stack pointer arg */
		jbsr trap_c /* Call C-level trap handler */
		@@ -311,6 +335,7 @@ ENTRY(csky_get_tls)
		ENTRY(csky_irq)
		SAVE_ALL 0
		zero_fp
		context_tracking
		psrset ee

		#ifdef CONFIG_TRACE_IRQFLAGS

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