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 for <linuxppc-dev@lists.ozlabs.org> from <ldufour@linux.vnet.ibm.com>;
 Wed, 4 Oct 2017 07:50:59 +0100
Subject: Re: [PATCH v3 00/20] Speculative page faults
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>,
 Peter Zijlstra <peterz@infradead.org>,
 Andrew Morton <akpm@linux-foundation.org>, kirill@shutemov.name,
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 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Michael Ellerman <mpe@ellerman.id.au>, Paul Mackerras <paulus@samba.org>,
 Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
 "H. Peter Anvin" <hpa@zytor.com>, Will Deacon <will.deacon@arm.com>,
 Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
 "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
 linux-mm <linux-mm@kvack.org>, haren@linux.vnet.ibm.com,
 Anshuman Khandual <khandual@linux.vnet.ibm.com>, npiggin@gmail.com,
 bsingharora@gmail.com, Tim Chen <tim.c.chen@linux.intel.com>,
 linuxppc-dev@lists.ozlabs.org, "x86@kernel.org" <x86@kernel.org>
References: <CAADnVQLmSbLHwj9m33kpzAidJPvq3cbdnXjaew6oTLqHWrBbZQ@mail.gmail.com>
From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Date: Wed, 4 Oct 2017 08:50:49 +0200
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On 25/09/2017 18:27, Alexei Starovoitov wrote:
> On Mon, Sep 18, 2017 at 12:15 AM, Laurent Dufour
> <ldufour@linux.vnet.ibm.com> wrote:
>> Despite the unprovable lockdep warning raised by Sergey, I didn't get any
>> feedback on this series.
>>
>> Is there a chance to get it moved upstream ?
> 
> what is the status ?
> We're eagerly looking forward for this set to land,
> since we have several use cases for tracing that
> will build on top of this set as discussed at Plumbers.

Hi Alexei,

Based on Plumber's note [1], it sounds that the use case is tied to the BPF
tracing where a call tp find_vma() call will be made on a process's context
to fetch user space's symbols.

Am I right ?
Is the find_vma() call made in the context of the process owning the mm
struct ?

Thanks,
Laurent.

[1] https://etherpad.openstack.org/p/LPC2017_Tracing)