On Monday 17 January 2005 05:07 pm, Bjoern A. Zeeb wrote: > Hi, > > I have added the following as LOR #055 to "the LOR page"[1]. > > lock order reversal > 1st 0xffffffff80c3a9e8 sleep mtxpool (sleep mtxpool) _at_ > sys/kern/kern_descrip.c:2277 2nd 0xffffff00222d8a48 filedesc structure > (filedesc structure) _at_ sys/kern/kern_descrip.c:2278 KDB: stack backtrace: > witness_checkorder() at witness_checkorder+0x5f1 > _mtx_lock_flags() at _mtx_lock_flags+0x4a > dupfdopen() at dupfdopen+0x320 > kern_open() at kern_open+0x5de > syscall() at syscall+0x4ab > Xfast_syscall() at Xfast_syscall+0xa8 > --- syscall (5, FreeBSD ELF64, open), rip = 0x80077e7d0, rsp = > 0x7fffffffe6f8, rbp = 0x7fffffffec70 --- > > I can easily reproduce it every boot. It seems to be triggered by > Capi4BSD[2] framework which I incorporated in my private tree. > > Can someone please comment on this ? The problem is that FILEDESC_UNLOCK() actually includes an entirely separate lock of its own (it's like an sx lock sort of). One possible fix might be to change struct file to either use a dedicated mutex pool (instead of the more generic mtxpool_sleep one that is intended only for leaf-lock usage) or to have each struct file include its own mutex rather than using a pool lock. -- John Baldwin <jhb_at_FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.orgReceived on Tue Jan 18 2005 - 17:08:44 UTC
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