[DragonFlyBSD - Bug #2353] panic: assertion "gd->gd_spinlocks_wr == 0" failed in bsd4_schedulerclock

[Venkatesh Srinivas via Redmine <bugtracker-admin@xxxxxxxxxxxxxxxxxxxxx>]

Issue #2353 has been updated by Venkatesh Srinivas.


Some preliminary debugging:

was in 'moused' thread, we were interrupted or somehow called splz. We were probably in a critical section; crit_exit can splz() itself.

splz
	++critcount from splz itself				(exp critcount=1)

	splz_timer
		lapic_timer_process
			lapic_timer_process_oncpu
				systimer_intr
					++crit_enter from systimer_intr		(exp.cc=2)
					++gd_syst_next from systimer_intr
					
					--crit_enter from systimer_intr		(exp.cc=1)

					schedclock [first systimer]

						lp = 'moused thread'

						bsd4_schedulerclock


						on CPU0; below rrinterval, no need_user_resched
                                                [exp.critcount=1, found cc=4]
							
			



					(pollclock)
					(emergency_intr_timer_callback)
					(hardclock)
					(statclock)
					

----------------------------------------
Bug #2353: panic: assertion "gd->gd_spinlocks_wr == 0" failed in bsd4_schedulerclock
http://bugs.dragonflybsd.org/issues/2353

Author: Joachim de Groot
Status: New
Priority: Normal
Assignee: 
Category: 
Target version: 


Version String: DragonFly v3.1.0.322.gc231b-DEVELOPMENT #0: Fri Mar 16 20:31:33 CET 2012

#0  _get_mycpu () at ./machine/thread.h:69
#1  md_dumpsys (di=<optimized out>) at /usr/src/sys/platform/pc64/x86_64/dump_machdep.c:263
#2  0xffffffff802fb2d2 in dumpsys () at /usr/src/sys/kern/kern_shutdown.c:937
#3  0xffffffff802fb936 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:387
#4  0xffffffff802fbbed in panic (fmt=0xffffffff80585cf0 "assertion \"%s\" failed in %s at %s:%u") at /usr/src/sys/kern/kern_shutdown.c:843
#5  0xffffffff803036fb in bsd4_schedulerclock (lp=<optimized out>, period=<optimized out>, cpstamp=<optimized out>) at /usr/src/sys/kern/usched_bsd4.c:622
#6  0xffffffff802db16c in schedclock (info=0xffffffff820106e8, in_ipi=<optimized out>, frame=<optimized out>) at /usr/src/sys/kern/kern_clock.c:776
#7  0xffffffff802f9e03 in systimer_intr (timep=<optimized out>, in_ipi=<optimized out>, frame=0x0) at /usr/src/sys/kern/kern_systimer.c:102
#8  0xffffffff8054ad04 in lapic_timer_process_oncpu (gd=0xffffffff8200f000, frame=0x0) at /usr/src/sys/platform/pc64/apic/lapic.c:336
#9  0xffffffff8054ad3c in lapic_timer_process () at /usr/src/sys/platform/pc64/apic/lapic.c:342
#10 0xffffffff80540d69 in splz_timer () at /usr/src/sys/platform/pc64/x86_64/ipl.s:461
#11 0x0000000000000000 in ?? ()

Before dumping, several text blocks like this one were emitted:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; lapic->id = 00000000
fault virtual address   = 0x20
fault code              = supervisor write data, page not present
instruction pointer     = 0x8:0xffffffff802ec7fc
stack pointer           = 0x10:0xffffffe0a8b4a980
frame pointer           = 0x10:0xffffffe0a8b4a9c8
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 0, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 8139
current thread          = pri 6 (CRIT)
kernel: type 12 trap, code=2

A dump is available.


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