From owner-freebsd-current@freebsd.org Sat May 9 20:47:51 2020 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 4646B2F548B for ; Sat, 9 May 2020 20:47:51 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 49KK5g0CDVz4JyK; Sat, 9 May 2020 20:47:50 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id 049KlhYE071227 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sat, 9 May 2020 23:47:46 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 049KlhYE071227 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id 049Klhi2071226; Sat, 9 May 2020 23:47:43 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sat, 9 May 2020 23:47:43 +0300 From: Konstantin Belousov To: Andriy Gapon Cc: FreeBSD Current Subject: Re: CHANGE_PV_LIST_LOCK_TO_PHYS is not correct when !NUMA ? Message-ID: <20200509204743.GA68906@kib.kiev.ua> References: <0d7db402-621e-cc6b-2918-2078f63e2a9b@FreeBSD.org> <20200508161500.GC44519@kib.kiev.ua> <6485ab77-a3d0-8916-9431-74e4da1e3ea7@FreeBSD.org> <20200509161325.GH44519@kib.kiev.ua> <20200509165010.GI44519@kib.kiev.ua> <88ebc8f9-b10d-366d-a12a-fb74417904bc@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <88ebc8f9-b10d-366d-a12a-fb74417904bc@FreeBSD.org> X-Spam-Status: No, score=-0.9 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED,PLING_QUERY autolearn=no autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on tom.home X-Rspamd-Queue-Id: 49KK5g0CDVz4JyK X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-6.00 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.32 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 May 2020 20:47:51 -0000 On Sat, May 09, 2020 at 11:33:40PM +0300, Andriy Gapon wrote: > On 09/05/2020 19:50, Konstantin Belousov wrote: > > On Sat, May 09, 2020 at 07:16:27PM +0300, Andriy Gapon wrote: > >> On 09/05/2020 19:13, Konstantin Belousov wrote: > >>> On Sat, May 09, 2020 at 06:52:24PM +0300, Andriy Gapon wrote: > >>>> On 08/05/2020 19:15, Konstantin Belousov wrote: > >>>>> On Fri, May 08, 2020 at 06:53:24PM +0300, Andriy Gapon wrote: > >>>>>> > >>>>>> I have a reproducible panic with a custom kernel without option NUMA while using > >>>>>> amdgpu driver from linuxkpi-based drm: > >>>>>> > >>>>>> panic: address 41ec00000 beyond the last segment > >>>>>> > >>>>>> I did some quick debugging and the panic happens when Xorg server tries to > >>>>>> access a frame buffer (or something like that). There is a page fault that gets > >>>>>> satisfied by ttm with a fictitious page. > >>>>>> > >>>>>> The stack trace is: > >>>>>> #11 0xffffffff808031a3 in panic (fmt=0xffffffff8119a998 > >>>>>> "5\003ʀ\377\377\377\377") at /usr/devel/git/motil/sys/kern/kern_shutdown.c:839 > >>>>>> #12 0xffffffff80bbc552 in pmap_enter (pmap=, va=34504441856, > >>>>>> m=, prot=, flags=, psind= >>>>>> out>) at /usr/devel/git/motil/sys/amd64/amd64/pmap.c:6035 > >>>>>> #13 0xffffffff80b288be in vm_fault_populate (fs=) at > >>>>>> /usr/devel/git/motil/sys/vm/vm_fault.c:519 > >>>>>> #14 vm_fault_allocate (fs=) at > >>>>>> /usr/devel/git/motil/sys/vm/vm_fault.c:1032 > >>>>>> #15 vm_fault (map=, vaddr=, fault_type= >>>>>> out>, fault_flags=, m_hold=) at > >>>>>> /usr/devel/git/motil/sys/vm/vm_fault.c:1342 > >>>>>> #16 0xffffffff80b26e7e in vm_fault_trap (map=0xfffffe0017cd39e8, > >>>>>> vaddr=, fault_type=, fault_flags=0, > >>>>>> signo=0xfffffe00a810dbc4, ucode=0xfffffe00a810dbc0) at > >>>>>> /usr/devel/git/motil/sys/vm/vm_fault.c:589 > >>>>>> #17 0xffffffff80bcf89c in trap_pfault (frame=0xfffffe00a810dc00, > >>>>>> usermode=, signo=, ucode=0xffffffff80853250 > >>>>>> ) at /usr/devel/git/motil/sys/amd64/amd64/trap.c:821 > >>>>>> #18 0xffffffff80bceeec in trap (frame=0xfffffe00a810dc00) at > >>>>>> /usr/devel/git/motil/sys/amd64/amd64/trap.c:34 > >>>>>> > >>>>>> > >>>>>> The line number in pmap_enter() is incorrect, I guess because of optimizations. > >>>>>> The assert seems to be reached via pmap_enter -> CHANGE_PV_LIST_LOCK_TO_PHYS -> > >>>>>> PHYS_TO_PV_LIST_LOCK -> pa_index(). > >>>>>> > >>>>>> The panic in correct in that the page is fictitious and its physical address is > >>>>>> beyond the end of real physical memory. > >>>>>> It seems that NUMA PHYS_TO_PV_LIST_LOCK() is aware of such pages, but !NUMA one > >>>>>> is not. > >>>>> > >>>>> I think you can remove this assert. pa_index() is always taken by > >>>>> % NVP_LIST_LOCKS, because fictitious mappings are not promoted. > >>>>> > >>>>> Try that and commit if it works for you. > >>>> > >>>> I tried this change: > >>>> diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c > >>>> index 4deed86a76d1a..b834b7f0388b7 100644 > >>>> --- a/sys/amd64/amd64/pmap.c > >>>> +++ b/sys/amd64/amd64/pmap.c > >>>> @@ -345,7 +345,7 @@ pmap_pku_mask_bit(pmap_t pmap) > >>>> #define NPV_LIST_LOCKS MAXCPU > >>>> > >>>> #define PHYS_TO_PV_LIST_LOCK(pa) \ > >>>> - (&pv_list_locks[pa_index(pa) % NPV_LIST_LOCKS]) > >>>> + (&pv_list_locks[((pa) >> PDRSHIFT) % NPV_LIST_LOCKS]) > >>>> #endif > >>>> > >>>> #define CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, pa) do { \ > >>>> > >>>> It fixed the original problem, but I got a new panic. > >>>> "DI already started" in pmap_remove() -> pmap_delayed_invl_start_u(). > >>>> I guess that !NUMA variant does not get much testing, so I'll probably just > >>>> stick with the default. > >>> Why didn't you just removed the KASSERT from pa_index ? > >> > >> Well, I thought it might be useful in the NUMA case. > >> pa_index() definition is shared between both cases. > > Might be define the macro two times, for NUMA/non-NUMA. non-NUMA case > > does not need the assert, because users take it mod NPV_LIST_LOCKS. > > > > I still don't see how that could help with "DI already started" panic. Might be not, might be it would help due to pmap_delayed_invl_genp(). But I would more worry about this 'already started' issue, because this must not happen. Can you remove the assert from the macro and provide backtrace of 'DI already started' panic ?