From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 05/18] Add io_uring IO interface
Date: Tue, 29 Jan 2019 09:28:01 -0700
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To: Arnd Bergmann <arnd@arndb.de>
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On 1/29/19 9:26 AM, Arnd Bergmann wrote:
> On Tue, Jan 29, 2019 at 5:19 PM Jens Axboe <axboe@kernel.dk> wrote:
>> On 1/29/19 9:18 AM, Arnd Bergmann wrote:
>>> On Tue, Jan 29, 2019 at 4:20 PM Jens Axboe <axboe@kernel.dk> wrote:
>>>> That's good info. I am currently using set_user_sigmask() for it.
>>>> I'd really like to avoid having to pass in a sigset_t size for the
>>>> system call, however.
>>>
>>> I really wouldn't do it, given that all other signal handling interfaces
>>> are prepared for longer signal masks. You /could/ probably extend
>>> it later with a flags bit to signify a longer mask instead of using
>>> the entire register to hold the bit length, it just seems really
>>> inconsistent with all other system calls.
>>
>> Damnit! OK, I'll keep what I currently have then.
> 
> As long as you stay within the 6-argument syscall contraints,
> the cost of passing the length is basically free, right?
> 
> Is there anything else you are worried about?

My main worry is not the extra argument, more that we're at capacity
for the system call. If we wanted to add a timeout parameter, then we'd
need to bundle them up, which sucks.

But I think we're fine, I'll go with what I have.

-- 
Jens Axboe

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