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Subject: Re: raid0 vs. mkfs
To: Coly Li <colyli@suse.de>, Shaohua Li <shli@kernel.org>
Cc: NeilBrown <neilb@suse.com>, linux-raid@vger.kernel.org,
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From: Avi Kivity <avi@scylladb.com>
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Date: Thu, 29 Jun 2017 18:15:43 +0300
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On 12/08/2016 06:44 PM, Coly Li wrote:
> On 2016/12/8 上午12:59, Shaohua Li wrote:
>> On Wed, Dec 07, 2016 at 07:50:33PM +0800, Coly Li wrote:
> [snip]
>> Thanks for doing this, Coly! For raid0, this totally makes sense. The raid0
>> zones make things a little complicated though. I just had a brief look of your
>> proposed patch, which looks really complicated. I'd suggest something like
>> this:
>> 1. split the bio according to zone boundary.
>> 2. handle the splitted bio. since the bio is within zone range, calculating
>> the start and end sector for each rdev should be easy.
>>
> Hi Shaohua,
>
> Thanks for your suggestion! I try to modify the code by your suggestion,
> it is even more hard to make the code that way ...
>
> Because even split bios for each zone, all the corner cases still exist
> and should be taken care in every zoon. The code will be more complicated.
>

Hi Coly,

Did you manage to complete this patch? We are seeing its effect, not 
only with mkfs, but also with fstrim(8).

Avi