Date: Tue, 04 Oct 2005 23:41:57 +0400 From: Roman Kurakin <rik@cronyx.ru> To: John Baldwin <jhb@FreeBSD.org> Cc: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>, FreeBSD current mailing list <current@FreeBSD.org> Subject: Re: LOR: kern_descrip.c:2277,2278 Message-ID: <4342DB05.10608@cronyx.ru> In-Reply-To: <200510031306.31314.jhb@FreeBSD.org> References: <Pine.BSF.4.53.0501172204330.70426@e0-0.zab2.int.zabbadoz.net> <200501181124.19323.jhb@FreeBSD.org> <4340E785.3030705@cronyx.ru> <200510031306.31314.jhb@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Commited. rik John Baldwin: >On Monday 03 October 2005 04:10 am, Roman Kurakin wrote: > > >>Hi, >> >>Could you check: >> >>http://lists.freebsd.org/pipermail/freebsd-current/2005-September/056078.ht >>ml >> >>Best regards, >> rik >> >> > >If it doesn't trigger any other LORs then it is probably fine. > > > >>John Baldwin wrote: >> >> >>>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) @ >>>>sys/kern/kern_descrip.c:2277 2nd 0xffffff00222d8a48 filedesc structure >>>>(filedesc structure) @ 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. >>> >>> > > >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4342DB05.10608>