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Date: Mon, 5 Dec 2022 15:52:47 -0500
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Subject: Re: [PATCH 4.19 094/105] parisc: Increase size of gcc stack frame
 check
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To: Helge Deller <deller@gmx.de>, Arnd Bergmann <arnd@arndb.de>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org
Cc: patches@lists.linux.dev, Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>,
 Christoph Hellwig <hch@infradead.org>, Sasha Levin <sashal@kernel.org>
References: <20221205190803.124472741@linuxfoundation.org>
 <20221205190806.296201818@linuxfoundation.org>
 <dfa8305f-f52f-4322-a22e-9a1e90fcfad4@app.fastmail.com>
 <4676311f-1c08-a611-a3be-48e841093e45@gmx.de>
From: John David Anglin <dave.anglin@bell.net>
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On 2022-12-05 2:58 p.m., Helge Deller wrote:
>> My understanding of the parisc overhead was that this
>> was just based on a few bytes per function call,
>
> What exactly do you mean by a few bytes?
> On parisc the frame size is a multiple of 64-bytes (on 32-bit)
> and 128 bytes (on 64bit).
On 64bit, the frame size alignment is actually 16 bytes.  The minimum frame size is 80 bytes.
That's 16 bytes for the frame marker and 64 bytes for the register save area.

Dave

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