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From: John David Anglin <dave.anglin@bell.net>
To: Rolf Eike Beer <eike-kernel@sf-tec.de>,
	linux-parisc <linux-parisc@vger.kernel.org>
Cc: Helge Deller <deller@gmx.de>, Deller <deller@kernel.org>,
	James Bottomley <James.Bottomley@hansenpartnership.com>
Subject: Re: [PATCH] parisc: Fix mask used to select futex spinlock
Date: Tue, 21 Dec 2021 14:27:19 -0500	[thread overview]
Message-ID: <7ec01f4d-e0e4-b01f-246a-0185fe2d8111@bell.net> (raw)
In-Reply-To: <5778770.lOV4Wx5bFT@daneel.sf-tec.de>

On 2021-12-21 1:45 p.m., Rolf Eike Beer wrote:
> Am Dienstag, 21. Dezember 2021, 19:33:16 CET schrieb John David Anglin:
>> Fix mask used to select futex spinlock.
>>
>> The address bits used to select the futex spinlock need to match those used
>> in the LWS code in syscall.S. The mask 0x3f8 only selects 7 bits.  It
>> should select 8 bits.
> This change looks like this should become a helper macro or something like
> that so the code will stay in sync. Can the mask be shared with the LWS code
> with a constant while at it so it will also include that?
I understand the point but it's rather convoluted.  We would need a macro for the assembly
code.  Then the macro would need to be embedded in an asm for C. Then, there's the shift
for the int* type in the C code.

I am proposing to rewrite this code so the spinlock pointer is only computed once, but Helge
wanted a change that could be easily back ported.

Dave

-- 
John David Anglin  dave.anglin@bell.net


  reply	other threads:[~2021-12-21 19:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-21 18:33 [PATCH] parisc: Fix mask used to select futex spinlock John David Anglin
2021-12-21 18:45 ` Rolf Eike Beer
2021-12-21 19:27   ` John David Anglin [this message]
2021-12-21 19:33     ` Helge Deller

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