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Date: Mon, 4 Jul 2022 22:36:54 +0700
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To: Jens Axboe <axboe@kernel.dk>
Cc: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>,
 Fernanda Ma'rouf <fernandafmr12@gnuweeb.org>,
 Pavel Begunkov <asml.silence@gmail.com>, Hao Xu <howeyxu@tencent.com>,
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References: <20220629175255.1377052-1-ammar.faizi@intel.com>
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 <49ed1c4c-46ca-15c4-f288-f6808401b0ff@kernel.dk>
From: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Subject: Re: [PATCH liburing v2 0/8] aarch64 support
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On 7/4/22 8:05 PM, Jens Axboe wrote:
> On 7/4/22 6:52 AM, Ammar Faizi wrote:
>> This no longer applies, I will send v3 revision soon. If you have some
>> comments, let me know so I can address it together with the rebase.
> 
> Just send a v3, didn't have time to go fully over it yet. One note,
> though - for patch 5, I'd split get_page_size() into two pieces so you
> just do:
> 
> static inline long get_page_size(void)
> {
> 	static long cache_val;
> 
> 	if (cache_val)
> 		return cache_val;
> 
> 	return __get_page_size();
> }
> 
> With that, we can have __get_page_size() just do that one thing, open
> the file and read the value.
> 
> No need to init static variables to 0.
> 
> And finally, if the read/open/whatever fails in __get_page_size(),
> assign cache_val to the fallback value as well. I don't see a point in
> retrying the same operation later and expect a different result.

OK, I got the idea, folded that in.

Also, it seems we don't have any test that hits that get_page_size()
path. Do we?

I am going to create a new test:

    test/nolibc.c

That file will test the nolibc functionality, let's do get_page_size()
for starting. We can compare the result with a libc function like:

   long a = sysconf(_SC_PAGESIZE);
   long b = get_page_size();
   if (a != b) {
         fprintf(stderr, "get_page_size() fails, %ld != %ld", a, b);
         return T_EXIT_FAIL;
   }

-- 
Ammar Faizi