From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1AB2C4361B for ; Thu, 17 Dec 2020 13:29:12 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BE39022E02 for ; Thu, 17 Dec 2020 13:29:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE39022E02 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43320 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kptLC-00012Q-Nr for qemu-devel@archiver.kernel.org; Thu, 17 Dec 2020 08:29:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:43642) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kptJx-00005Q-2a for qemu-devel@nongnu.org; Thu, 17 Dec 2020 08:27:53 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20296) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kptJs-0001oB-OL for qemu-devel@nongnu.org; Thu, 17 Dec 2020 08:27:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608211667; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=fcN1UDTE30qNALnBkD3BVEMwYUnsHOvNV3eVqMCCVDE=; b=DlyF3zggxt/oAIi6efcNQ/C46XfGZ4UA/7vYTMOdyuDcl1KhD0d8oiCVWkQ7uZd/dcS2oe qDOatT1UekAMBOCbeZjiVj14dKSpCIMBbeDAiXS7ctimzUQvVNvacpwgLLmO4Kfvt5E9nQ RSJI6qN7lIc0ccay0kCqvuvGTHTV78g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-199-abEwEbf0N_yVvfafwXb5ZQ-1; Thu, 17 Dec 2020 08:27:43 -0500 X-MC-Unique: abEwEbf0N_yVvfafwXb5ZQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 962D959; Thu, 17 Dec 2020 13:27:41 +0000 (UTC) Received: from localhost (ovpn-112-215.rdu2.redhat.com [10.10.112.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id 43B34E723; Thu, 17 Dec 2020 13:27:34 +0000 (UTC) Date: Thu, 17 Dec 2020 14:27:33 +0100 From: Sergio Lopez To: Kevin Wolf Subject: Re: [PATCH v2 2/4] block: Avoid processing BDS twice in bdrv_set_aio_context_ignore() Message-ID: <20201217132733.cma4u2niu3texah3@mhamilton> References: <20201215131527.evpidxevevtfy54n@mhamilton> <20201215150119.GE8185@merkur.fritz.box> <20201215172337.w7vcn2woze2ejgco@mhamilton> <20201216123514.GD7548@merkur.fritz.box> <20201216145502.yiejsw47q5pfbzio@mhamilton> <20201216183102.GH7548@merkur.fritz.box> <20201217093744.tg6ik73o45nidcs4@mhamilton> <20201217105830.GA12328@merkur.fritz.box> <20201217130602.GB12328@merkur.fritz.box> MIME-Version: 1.0 In-Reply-To: <20201217130602.GB12328@merkur.fritz.box> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=slp@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="5763q23vvthyoprt" Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=slp@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, "Michael S. Tsirkin" , Paul Durrant , qemu-devel@nongnu.org, Max Reitz , Stefano Stabellini , Stefan Hajnoczi , xen-devel@lists.xenproject.org, Anthony Perard , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --5763q23vvthyoprt Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Dec 17, 2020 at 02:06:02PM +0100, Kevin Wolf wrote: > Am 17.12.2020 um 13:50 hat Vladimir Sementsov-Ogievskiy geschrieben: > > 17.12.2020 13:58, Kevin Wolf wrote: > > > Am 17.12.2020 um 10:37 hat Sergio Lopez geschrieben: > > > > On Wed, Dec 16, 2020 at 07:31:02PM +0100, Kevin Wolf wrote: > > > > > Am 16.12.2020 um 15:55 hat Sergio Lopez geschrieben: > > > > > > On Wed, Dec 16, 2020 at 01:35:14PM +0100, Kevin Wolf wrote: > > > > > > > Anyway, trying to reconstruct the block graph with BdrvChild = pointers > > > > > > > annotated at the edges: > > > > > > >=20 > > > > > > > BlockBackend > > > > > > > | > > > > > > > v > > > > > > > backup-top ------------------------+ > > > > > > > | | | > > > > > > > | +-----------------------+ | > > > > > > > | 0x5655068b8510 | | 0x565505e3c450 > > > > > > > | | | > > > > > > > | 0x565505e42090 | | > > > > > > > v | | > > > > > > > qcow2 ---------------------+ | | > > > > > > > | | | | > > > > > > > | 0x565505e52060 | | | ??? [1] > > > > > > > | | | | | > > > > > > > v 0x5655066a34d0 | | | | 0x565505fc7aa0 > > > > > > > file v v v v > > > > > > > qcow2 (backing) > > > > > > > | > > > > > > > | 0x565505e41d20 > > > > > > > v > > > > > > > file > > > > > > >=20 > > > > > > > [1] This seems to be a BdrvChild with a non-BDS parent. Proba= bly a > > > > > > > BdrvChild directly owned by the backup job. > > > > > > >=20 > > > > > > > > So it seems this is happening: > > > > > > > >=20 > > > > > > > > backup-top (5e48030) <---------| (5) > > > > > > > > | | | > > > > > > > > | | (6) ------------> qcow2 (5fbf660) > > > > > > > > | ^ | > > > > > > > > | (3) | | (4) > > > > > > > > |-> (1) qcow2 (5e5d420) ----- |-> file (6bc0c00) > > > > > > > > | > > > > > > > > |-> (2) file (5e52060) > > > > > > > >=20 > > > > > > > > backup-top (5e48030), the BDS that was passed as argument i= n the first > > > > > > > > bdrv_set_aio_context_ignore() call, is re-entered when qcow= 2 (5fbf660) > > > > > > > > is processing its parents, and the latter is also re-entere= d when the > > > > > > > > first one starts processing its children again. > > > > > > >=20 > > > > > > > Yes, but look at the BdrvChild pointers, it is through differ= ent edges > > > > > > > that we come back to the same node. No BdrvChild is used twic= e. > > > > > > >=20 > > > > > > > If backup-top had added all of its children to the ignore lis= t before > > > > > > > calling into the overlay qcow2, the backing qcow2 wouldn't ev= entually > > > > > > > have called back into backup-top. > > > > > >=20 > > > > > > I've tested a patch that first adds every child to the ignore l= ist, > > > > > > and then processes those that weren't there before, as you sugg= ested > > > > > > on a previous email. With that, the offending qcow2 is not re-e= ntered, > > > > > > so we avoid the crash, but backup-top is still entered twice: > > > > >=20 > > > > > I think we also need to every parent to the ignore list before ca= lling > > > > > callbacks, though it doesn't look like this is the problem you're > > > > > currently seeing. > > > >=20 > > > > I agree. > > > >=20 > > > > > > bs=3D0x560db0e3b030 (backup-top) enter > > > > > > bs=3D0x560db0e3b030 (backup-top) processing children > > > > > > bs=3D0x560db0e3b030 (backup-top) calling bsaci child=3D0x560db0= e2f450 (child->bs=3D0x560db0fb2660) > > > > > > bs=3D0x560db0fb2660 (qcow2) enter > > > > > > bs=3D0x560db0fb2660 (qcow2) processing children > > > > > > bs=3D0x560db0fb2660 (qcow2) calling bsaci child=3D0x560db0e34d2= 0 (child->bs=3D0x560db1bb3c00) > > > > > > bs=3D0x560db1bb3c00 (file) enter > > > > > > bs=3D0x560db1bb3c00 (file) processing children > > > > > > bs=3D0x560db1bb3c00 (file) processing parents > > > > > > bs=3D0x560db1bb3c00 (file) processing itself > > > > > > bs=3D0x560db0fb2660 (qcow2) calling bsaci child=3D0x560db16964d= 0 (child->bs=3D0x560db0e50420) > > > > > > bs=3D0x560db0e50420 (qcow2) enter > > > > > > bs=3D0x560db0e50420 (qcow2) processing children > > > > > > bs=3D0x560db0e50420 (qcow2) calling bsaci child=3D0x560db0e34ea= 0 (child->bs=3D0x560db0e45060) > > > > > > bs=3D0x560db0e45060 (file) enter > > > > > > bs=3D0x560db0e45060 (file) processing children > > > > > > bs=3D0x560db0e45060 (file) processing parents > > > > > > bs=3D0x560db0e45060 (file) processing itself > > > > > > bs=3D0x560db0e50420 (qcow2) processing parents > > > > > > bs=3D0x560db0e50420 (qcow2) processing itself > > > > > > bs=3D0x560db0fb2660 (qcow2) processing parents > > > > > > bs=3D0x560db0fb2660 (qcow2) calling set_aio_ctx child=3D0x560db= 1672860 > > > > > > bs=3D0x560db0fb2660 (qcow2) calling set_aio_ctx child=3D0x560db= 1b14a20 > > > > > > bs=3D0x560db0e3b030 (backup-top) enter > > > > > > bs=3D0x560db0e3b030 (backup-top) processing children > > > > > > bs=3D0x560db0e3b030 (backup-top) processing parents > > > > > > bs=3D0x560db0e3b030 (backup-top) calling set_aio_ctx child=3D0x= 560db0e332d0 > > > > > > bs=3D0x560db0e3b030 (backup-top) processing itself > > > > > > bs=3D0x560db0fb2660 (qcow2) processing itself > > > > > > bs=3D0x560db0e3b030 (backup-top) calling bsaci child=3D0x560db0= e35090 (child->bs=3D0x560db0e50420) > > > > > > bs=3D0x560db0e50420 (qcow2) enter > > > > > > bs=3D0x560db0e3b030 (backup-top) processing parents > > > > > > bs=3D0x560db0e3b030 (backup-top) processing itself > > > > > >=20 > > > > > > I see that "blk_do_set_aio_context()" passes "blk->root" to > > > > > > "bdrv_child_try_set_aio_context()" so it's already in the ignor= e list, > > > > > > so I'm not sure what's happening here. Is backup-top is referen= ced > > > > > > from two different BdrvChild or is "blk->root" not pointing to > > > > > > backup-top's BDS? > > > > >=20 > > > > > The second time that backup-top is entered, it is not as the BDS = of > > > > > blk->root, but as the parent node of the overlay qcow2. Which is > > > > > interesting, because last time it was still the backing qcow2, so= the > > > > > change did have _some_ effect. > > > > >=20 > > > > > The part that I don't understand is why you still get the line wi= th > > > > > child=3D0x560db1b14a20, because when you add all children to the = ignore > > > > > list first, that should have been put into the ignore list as one= of the > > > > > first things in the whole process (when backup-top was first ente= red). > > > > >=20 > > > > > Is 0x560db1b14a20 a BdrvChild that has backup-top as its opaque v= alue, > > > > > but isn't actually present in backup-top's bs->children? > > > >=20 > > > > Exactly, that line corresponds to this chunk of code: > > > >=20 > > > > <---- begin ----> > > > > QLIST_FOREACH(child, &bs->parents, next_parent) { > > > > if (g_slist_find(*ignore, child)) { > > > > continue; > > > > } > > > > assert(child->klass->set_aio_ctx); > > > > *ignore =3D g_slist_prepend(*ignore, child); > > > > fprintf(stderr, "bs=3D%p (%s) calling set_aio_ctx child=3D= %p\n", bs, bs->drv->format_name, child); > > > > child->klass->set_aio_ctx(child, new_context, ignore); > > > > } > > > > <---- end ----> > > > >=20 > > > > Do you think it's safe to re-enter backup-top, or should we look fo= r a > > > > way to avoid this? > > >=20 > > > I think it should be avoided, but I don't understand why putting all > > > children of backup-top into the ignore list doesn't already avoid it.= If > > > backup-top is in the parents list of qcow2, then qcow2 should be in t= he > > > children list of backup-top and therefore the BdrvChild should alread= y > > > be in the ignore list. > > >=20 > > > The only way I can explain this is that backup-top and qcow2 have > > > different ideas about which BdrvChild objects exist that connect them= . > > > Or that the graph changes between both places, but I don't see how th= at > > > could happen in bdrv_set_aio_context_ignore(). > > >=20 > >=20 > > bdrv_set_aio_context_ignore() do bdrv_drained_begin().. As I reported > > recently, nothing prevents some job finish and do graph modification > > during some another drained section. It may be the case. >=20 > Good point, this might be the same bug then. >=20 > If everything worked correctly, a job completion could only happen on > the outer bdrv_set_aio_context_ignore(). But after that, we are already > in a drain section, so the job should be quiesced and a second drain > shouldn't cause any additional graph changes. >=20 > I would have to go back to the other discussion, but I think it was > related to block jobs that are already in the completion process and > keep moving forward even though they are supposed to be quiesced. >=20 > If I remember correctly, actually pausing them at this point looked > difficult. Maybe what we should then do is letting .drained_poll return > true until they have actually fully completed? >=20 > Ah, but was this something that would deadlock because the job > completion callbacks use drain sections themselves? >=20 > > If backup-top involved, I can suppose that graph modification is in > > backup_clean, when we remove the filter.. Who is making > > set_aio_context in the issue? I mean, what is the backtrace of > > bdrv_set_aio_context_ignore()? >=20 > Sergio, can you provide the backtrace and also test if the theory with a > job completion in the middle of the process is what you actually hit? No, I'm sure the job is not finishing in the middle of the set_aio_context chain, which is started by a virtio_blk_data_plane_[start|stop], which in turn is triggered by a guest reboot. This is a stack trace that reaches to the point in which backup-top is entered a second time: #0 0x0000560c3e173bbd in child_job_set_aio_ctx (c=3D, ctx=3D0x560c40c45630, ignore=3D0x7f6d4eeb6f40) at= ../blockjob.c:159 #1 0x0000560c3e1aefc6 in bdrv_set_aio_context_ignore (bs=3D0x560c40dc3660, new_context=3D0x560c40c45630, ignore=3D0x7f6d4eeb= 6f40) at ../block.c:6509 #2 0x0000560c3e1aee8a in bdrv_set_aio_context_ignore (bs=3Dbs@entry=3D0x560c40c4c030, new_context=3Dnew_context@entry=3D0x56= 0c40c45630, ignore=3Dignore@entry=3D0x7f6d4eeb6f40) at ../block.c:6487 #3 0x0000560c3e1af503 in bdrv_child_try_set_aio_context (bs=3Dbs@entry=3D0x560c40c4c030, ctx=3Dctx@entry=3D0x560c40c45630, igno= re_child=3D, errp=3Derrp@entry=3D0x7f6d4eeb6fc8) at ../block= .c:6619 #4 0x0000560c3e1e561a in blk_do_set_aio_context (blk=3D0x560c41ca4610, new_context=3D0x560c40c45630, update_root_node= =3Dupdate_root_node@entry=3Dtrue, errp=3Derrp@entry=3D0x7f6d4eeb6fc8) at ..= /block/block-backend.c:2027 #5 0x0000560c3e1e740d in blk_set_aio_context (blk=3D, new_context=3D, errp=3Derrp@entr= y=3D0x7f6d4eeb6fc8) at ../block/block-backend.c:2048 #6 0x0000560c3e10de78 in virtio_blk_data_plane_start (vdev=3D) at ../hw/block/dataplane/virtio-blk.c:220 #7 0x0000560c3de691d2 in virtio_bus_start_ioeventfd (bus=3Dbus@entry=3D0x5= 60c41ca1e98) at ../hw/virtio/virtio-bus.c:222 #8 0x0000560c3de4f907 in virtio_pci_start_ioeventfd (proxy=3D0x560c41c99d9= 0) at ../hw/virtio/virtio-pci.c:1261 #9 0x0000560c3de4f907 in virtio_pci_common_write (opaque=3D0x560c41c99d90, addr=3D, val=3D= , size=3D) at ../hw/virtio/virtio-pci.c:1261 #10 0x0000560c3e145d81 in memory_region_write_accessor (mr=3D0x560c41c9a770, addr=3D20, value=3D, size=3D1, shi= ft=3D, mask=3D, attrs=3D...) at ../softmmu/me= mory.c:491 #11 0x0000560c3e1447de in access_with_adjusted_size (addr=3Daddr@entry=3D20, value=3Dvalue@entry=3D0x7f6d4eeb71a8, size=3Ds= ize@entry=3D1, access_size_min=3D, access_size_max=3D, access_fn=3D 0x560c3e145c80 , mr=3D0x560c41c9a770, att= rs=3D...) at ../softmmu/memory.c:552 #12 0x0000560c3e148052 in memory_region_dispatch_write (mr=3Dmr@entry=3D0x560c41c9a770, addr=3D20, data=3D, op= =3D, attrs=3Dattrs@entry=3D...) at ../softmmu/memory.c:1501 #13 0x0000560c3e06b5b7 in flatview_write_continue (fv=3Dfv@entry=3D0x7f6d400ed3e0, addr=3Daddr@entry=3D4261429268, attrs= =3D..., ptr=3Dptr@entry=3D0x7f6d71dad028, len=3Dlen@entry=3D1, addr1=3D, l=3D, mr=3D0x560c41c9a770) at /home/BZs/1900326/qemu/include/qemu/host-utils.h:164 #14 0x0000560c3e06b7d6 in flatview_write (fv=3D0x7f6d400ed3e0, addr=3Daddr@entry=3D4261429268, attrs=3Dattrs@ent= ry=3D..., buf=3Dbuf@entry=3D0x7f6d71dad028, len=3Dlen@entry=3D1) at ../soft= mmu/physmem.c:2799 #15 0x0000560c3e06e330 in address_space_write (as=3D0x560c3ec0a920 , addr=3D4261429268, attrs= =3D..., buf=3Dbuf@entry=3D0x7f6d71dad028, len=3D1) at ../softmmu/physmem.c:= 2891 #16 0x0000560c3e06e3ba in address_space_rw (as=3D, addr=3D, attrs=3D...,=20 attrs@entry=3D..., buf=3Dbuf@entry=3D0x7f6d71dad028, len=3D, is_write=3D) at ../softmmu/physmem.c:2901 #17 0x0000560c3e10021a in kvm_cpu_exec (cpu=3Dcpu@entry=3D0x560c40d7e0d0) a= t ../accel/kvm/kvm-all.c:2541 #18 0x0000560c3e1445e5 in kvm_vcpu_thread_fn (arg=3Darg@entry=3D0x560c40d7e= 0d0) at ../accel/kvm/kvm-cpus.c:49 #19 0x0000560c3e2c798a in qemu_thread_start (args=3D) at ../= util/qemu-thread-posix.c:521 #20 0x00007f6d6ba8614a in start_thread () at /lib64/libpthread.so.0 #21 0x00007f6d6b7b8763 in clone () at /lib64/libc.so.6 Thanks, Sergio. --5763q23vvthyoprt Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEvtX891EthoCRQuii9GknjS8MAjUFAl/bXMQACgkQ9GknjS8M AjWHbhAAqAynHW2PvCqRDO5Fkb14jQqz48cxSOsYnnLgsq18xpQ7SiA9pHN83zjJ FBKwp2KYzTbaFF5Ojs/2JTlJBg/6ZZm+2nAXLTuMrQjQbR8ugjYB5iUk4F5ox48h NYrmczZK5oCUbHcbXkTa8H1YyVUo7xkx0F9JDG+GUTgKuazK6edwnE7k///+JmQK 1au5ggmctwQZp2eLuX2Z0Y2cLAjkDSeSuweXH7LcAsEyf1GdlAxYVB1J0r6UXoMV 5wxaTiHJdAubwGubfeLbAfMC/v9FohtQ4VVRiOSA0P7UfJDp4pFgefNjvxwBItwR LNc3ldk0eIGnWdt7+de0p5B6ObtMbbSqxIE3gJCLswjlZ8zjzLCnSWDJ+XJ88nx7 78wkC4KtM6fCeMeYlahVFd8Kl4e/ykVq71H9W2XKgKwRQXH218DW7U7T2yqIGugw a6iECkEVhEksbaW5qFJvYgUH7N0hYV/InuKx5aq5f1tPD9TdTv0dPXXPkhR6r4vB 3B3FPQ13LEEBjIHcg9ygOElwqo3kWDOXPb4Ms/RGoRSGqD3eeObewLBsjzddpe7A Vy977Bn7vrVs5hSar3e66QX2KmGFScgHAmedXOIrnM0299NCw4kCwhCF5x7hJ2Fd OXtJhXA08Uo4q/FW8WJl9Sd/KWIa2mdVB8g+yCYYfj15i8B+N2A= =zHsJ -----END PGP SIGNATURE----- --5763q23vvthyoprt--