Date: Mon, 19 Sep 2016 18:05:46 -0700 From: John Baldwin <jhb@freebsd.org> To: Slawa Olhovchenkov <slw@zxy.spb.ru> Cc: freebsd-stable@freebsd.org Subject: Re: nginx and FreeBSD11 Message-ID: <2122051.7RxZBKUSFc@ralph.baldwin.cx> In-Reply-To: <20160918162241.GE2960@zxy.spb.ru> References: <20160907191348.GD22212@zxy.spb.ru> <1823460.vTm8IvUQsF@ralph.baldwin.cx> <20160918162241.GE2960@zxy.spb.ru>
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On Sunday, September 18, 2016 07:22:41 PM Slawa Olhovchenkov wrote:
> On Thu, Sep 15, 2016 at 10:28:11AM -0700, John Baldwin wrote:
>
> > On Thursday, September 15, 2016 05:41:03 PM Slawa Olhovchenkov wrote:
> > > On Wed, Sep 07, 2016 at 10:13:48PM +0300, Slawa Olhovchenkov wrote:
> > >
> > > > I am have strange issuse with nginx on FreeBSD11.
> > > > I am have FreeBSD11 instaled over STABLE-10.
> > > > nginx build for FreeBSD10 and run w/o recompile work fine.
> > > > nginx build for FreeBSD11 crushed inside rbtree lookups: next node
> > > > totaly craped.
> > > >
> > > > I am see next potential cause:
> > > >
> > > > 1) clang 3.8 code generation issuse
> > > > 2) system library issuse
> > > >
> > > > may be i am miss something?
> > > >
> > > > How to find real cause?
> > >
> > > I find real cause and this like show-stopper for RELEASE.
> > > I am use nginx with AIO and AIO from one nginx process corrupt memory
> > > from other nginx process. Yes, this is cross-process memory
> > > corruption.
> > >
> > > Last case, core dumped proccess with pid 1060 at 15:45:14.
> > > Corruped memory at 0x860697000.
> > > I am know about good memory at 0x86067f800.
> > > Dumping (form core) this region to file and analyze by hexdump I am
> > > found start of corrupt region -- offset 0000c8c0 from 0x86067f800.
> > > 0x86067f800+0xc8c0 = 0x86068c0c0
> > >
> > > I am preliminary enabled debuggin of AIO started operation to nginx
> > > error log (memory address, file name, offset and size of transfer).
> > >
> > > grep -i 86068c0c0 error.log near 15:45:14 give target file.
> > > grep ce949665cbcd.hls error.log near 15:45:14 give next result:
> > >
> > > 2016/09/15 15:45:13 [notice] 1055#0: *11659936 AIO_RD 000000082065DB60 start 000000086068C0C0 561b0 2646736 ce949665cbcd.hls
> > > 2016/09/15 15:45:14 [notice] 1060#0: *10998125 AIO_RD 000000081F1FFB60 start 000000086FF2C0C0 6cdf0 140016832 ce949665cbcd.hls
> > > 2016/09/15 15:45:14 [notice] 1055#0: *11659936 AIO_RD 00000008216B6B60 start 000000086472B7C0 7ff70 2999424 ce949665cbcd.hls
> >
> > Does nginx only use AIO for regular files or does it also use it with sockets?
> >
> > You can try using this patch as a diagnostic (you will need to
> > run with INVARIANTS enabled, or at least enabled for vfs_aio.c):
> >
> > Index: vfs_aio.c
> > ===================================================================
> > --- vfs_aio.c (revision 305811)
> > +++ vfs_aio.c (working copy)
> > @@ -787,6 +787,8 @@ aio_process_rw(struct kaiocb *job)
> > * aio_aqueue() acquires a reference to the file that is
> > * released in aio_free_entry().
> > */
> > + KASSERT(curproc->p_vmspace == job->userproc->p_vmspace,
> > + ("%s: vmspace mismatch", __func__));
> > if (cb->aio_lio_opcode == LIO_READ) {
> > auio.uio_rw = UIO_READ;
> > if (auio.uio_resid == 0)
> > @@ -1054,6 +1056,8 @@ aio_switch_vmspace(struct kaiocb *job)
> > {
> >
> > vmspace_switch_aio(job->userproc->p_vmspace);
> > + KASSERT(curproc->p_vmspace == job->userproc->p_vmspace,
> > + ("%s: vmspace mismatch", __func__));
> > }
> >
> > If this panics, then vmspace_switch_aio() is not working for
> > some reason.
>
> I am try using next DTrace script:
> ====
> #pragma D option dynvarsize=64m
>
> int req[struct vmspace *, void *];
> self int trace;
>
> syscall:freebsd:aio_read:entry
> {
> this->aio = *(struct aiocb *)copyin(arg0, sizeof(struct aiocb));
> req[curthread->td_proc->p_vmspace, this->aio.aio_buf] = curthread->td_proc->p_pid;
> }
>
> fbt:kernel:aio_process_rw:entry
> {
> self->job = args[0];
> self->trace = 1;
> }
>
> fbt:kernel:aio_process_rw:return
> /self->trace/
> {
> req[self->job->userproc->p_vmspace, self->job->uaiocb.aio_buf] = 0;
> self->job = 0;
> self->trace = 0;
> }
>
> fbt:kernel:vn_io_fault:entry
> /self->trace && !req[curthread->td_proc->p_vmspace, args[1]->uio_iov[0].iov_base]/
> {
> this->buf = args[1]->uio_iov[0].iov_base;
> printf("%Y vn_io_fault %p:%p pid %d\n", walltimestamp, curthread->td_proc->p_vmspace, this->buf, req[curthread->td_proc->p_vmspace, this->buf]);
> }
> ===
>
> And don't got any messages near nginx core dump.
> What I can check next?
> May be check context/address space switch for kernel process?
Which CPU are you using? Perhaps try disabling PCID support (I think vm.pmap.pcid_enabled=0 from
loader prompt or loader.conf)? (Wondering if pmap_activate() is somehow not switching)
--
John Baldwin
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