From: Nicholas Piggin <npiggin@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@ozlabs.org, aneesh.kumar@linux.vnet.ibm.com,
anton@samba.org
Subject: Re: [PATCH] powerpc/mm/radix: Drop support for CPUs without lockless tlbie
Date: Wed, 3 May 2017 15:36:35 +1000 [thread overview]
Message-ID: <20170503153635.707ea5b6@roar.ozlabs.ibm.com> (raw)
In-Reply-To: <1493786699-14850-1-git-send-email-mpe@ellerman.id.au>
On Wed, 3 May 2017 14:44:59 +1000
Michael Ellerman <mpe@ellerman.id.au> wrote:
> Currently the radix TLB code includes support for CPUs that do *not*
> have MMU_FTR_LOCKLESS_TLBIE. On those CPUs we are required to take a
> global spinlock before issuing a tlbie.
>
> Radix can only be built for 64-bit Book3s CPUs, and of those, only
> POWER4, 970, Cell and PA6T do not have MMU_FTR_LOCKLESS_TLBIE. Although
> it's possible to build a kernel with Radix support that can also boot on
> those CPUs, we happen to know that in reality none of those CPUs support
> the Radix MMU, so the code can never actually run on those CPUs.
>
> So remove the native_tlbie_lock in the Radix TLB code.
>
> Note that there is another lock of the same name in the hash code, which
> is unaffected by this patch.
>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Good idea.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
next prev parent reply other threads:[~2017-05-03 5:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-03 4:44 [PATCH] powerpc/mm/radix: Drop support for CPUs without lockless tlbie Michael Ellerman
2017-05-03 5:36 ` Nicholas Piggin [this message]
2017-05-03 22:19 ` Michael Ellerman
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