From: Michael Ellerman <mpe@ellerman•id.au>
To: Nicholas Piggin <npiggin@gmail•com>,
Andreas Schwab <schwab@linux-m68k•org>
Cc: linuxppc-dev@ozlabs•org
Subject: Re: 4.13-rc3: Unrecoverable exception 4100
Date: Mon, 07 Aug 2017 19:56:28 +1000 [thread overview]
Message-ID: <877eyfpupf.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170805233917.72e49d2f@roar.ozlabs.ibm.com>
Nicholas Piggin <npiggin@gmail•com> writes:
> On Fri, 04 Aug 2017 21:54:57 +0200
> Andreas Schwab <schwab@linux-m68k•org> wrote:
>
>> No, this is really a 4.13-rc1 regression.
>>
>> Andreas.
>>
>
> SLB miss with MSR[RI]=0 on
>
> lbz r0,THREAD+THREAD_LOAD_FP(r7)
>
> Caused by bc4f65e4cf9d6cc43e0e9ba0b8648cf9201cd55f
Ah of course. Not sure why I haven't seen it in any of my testing :/
> Hmm, I'll see if something can be done, but that MSR_RI stuff in syscall
> exit makes things fairly difficult (and will reduce performance improvement
> of this patch anyway).
>
> I'm trying to work to a point where we have a soft-RI bit for these kinds of
> uses that would avoid all this complexity. Until then it may be best to
> just revert this patch.
OK. Let me know in the next day or two what you want to do.
One option would be to load THREAD_LOAD_FP/THREAD_LOAD_VEC before we
turn off RI.
It would be ugly, but if we think we can clean it up in the medium term
with soft-RI then maybe that would be OK.
cheers
next prev parent reply other threads:[~2017-08-07 9:56 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87vam3lhtn.fsf__12885.8019285419$1501844971$gmane$org@linux-m68k.org>
2017-08-04 19:39 ` 4.13-rc3: Unrecoverable exception 4100 Andreas Schwab
[not found] ` <87fud7ktqf.fsf__17563.3519575515$1501875675$gmane$org@linux-m68k.org>
2017-08-04 19:54 ` Andreas Schwab
2017-08-05 13:39 ` Nicholas Piggin
2017-08-07 9:56 ` Michael Ellerman [this message]
2017-08-07 10:26 ` Nicholas Piggin
2017-08-07 11:49 ` Michael Ellerman
2017-08-07 10:40 ` Andreas Schwab
2017-08-07 11:20 ` Michael Ellerman
2017-08-04 10:59 Andreas Schwab
2017-08-04 13:00 ` Benjamin Herrenschmidt
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