From: Helge Deller <deller@gmx.de>
To: Sven Schnelle <svens@stackframe.org>,
John David Anglin <dave.anglin@bell.net>
Cc: linux-parisc <linux-parisc@vger.kernel.org>,
James Bottomley <James.Bottomley@HansenPartnership.com>
Subject: Re: [PATCH] parisc: Remove lock code to serialize TLB operations in pacache.S
Date: Wed, 17 Apr 2019 23:01:12 +0200 [thread overview]
Message-ID: <a8829e22-e5e7-a896-5cd3-0cc82a96c227@gmx.de> (raw)
In-Reply-To: <19e13735-bfe6-531a-1920-d8955546040e@gmx.de>
On 17.04.19 22:58, Helge Deller wrote:
> On 17.04.19 22:55, Sven Schnelle wrote:
>> On Fri, Apr 12, 2019 at 07:12:04PM -0400, John David Anglin wrote:
>>> TLB operations only need to be serialized on machines with the Merced (Stretch) bus.
>>> The only machines in this category are L and N class, and they require a 64-bit PA 2.0
>>> kernel. On these machines, we use local TLB purges in the tmpalias routines. We don't
>>> need to serialize TLB purges on all other machines. Thus, the lock/unlock code can be
>>> removed when CONFIG_PA20 is not defined. Further, when CONFIG_PA20 is not defined,
>>> alternative patching converts the TLB purges to local purges when PA 2.0 hardware has
>>> been detected.
>>>
>>> Signed-off-by: John David Anglin <dave.anglin@bell.net>
>>
>> I had this patch running on my C8000 and J5000 for a few days, and haven't
>> encountered any issues.
>
> Nah...
> I do have one of the critical machines (rp5470), and I tried
> to add the necessary code to detect and handle the TLB serialization.
> Until now the patch sadly doesn't work yet (hangs at boot), it still needs more work.
> You can find it in my git tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?h=tlb-flush-merced-bus&id=fc6044f83cb9828ec6ebecb23a46549d9ebc518f
Please ignore my comments.
Dave's patch is OK.
I mixed it up with the Mikulas Patocka's patch: "use per-pagetable spinlock"
https://patchwork.kernel.org/patch/10888249/
Helge
next prev parent reply other threads:[~2019-04-17 21:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-12 23:12 [PATCH] parisc: Remove lock code to serialize TLB operations in pacache.S John David Anglin
2019-04-17 20:55 ` Sven Schnelle
2019-04-17 20:58 ` Helge Deller
2019-04-17 21:01 ` Helge Deller [this message]
2019-04-17 21:09 ` John David Anglin
2019-04-17 23:21 ` John David Anglin
2019-04-17 21:04 ` John David Anglin
2019-04-21 23:37 ` John David Anglin
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