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Message-ID: <1b99068c-ac1b-4121-93f4-23ba4863b8b0@pankajraghav.com>
Date: Tue, 26 Mar 2024 16:06:02 +0100
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Subject: Re: [PATCH v3 00/11] enable bs > ps in XFS
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To: Hannes Reinecke <hare@suse.de>, Matthew Wilcox <willy@infradead.org>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
 gost.dev@samsung.com, chandan.babu@oracle.com, mcgrof@kernel.org,
 djwong@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
 david@fromorbit.com, akpm@linux-foundation.org,
 Pankaj Raghav <p.raghav@samsung.com>
References: <20240313170253.2324812-1-kernel@pankajraghav.com>
 <ZgHOK9T2K9HKkju1@casper.infradead.org>
 <2508c03b-c26c-42ce-872d-3c5107a4d8a0@suse.de>
From: Pankaj Raghav <kernel@pankajraghav.com>
In-Reply-To: <2508c03b-c26c-42ce-872d-3c5107a4d8a0@suse.de>
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On 26/03/2024 10:53, Hannes Reinecke wrote:
> On 3/25/24 20:19, Matthew Wilcox wrote:
>> On Wed, Mar 13, 2024 at 06:02:42PM +0100, Pankaj Raghav (Samsung) wrote:
>>> This is the third version of the series that enables block size > page size
>>> (Large Block Size) in XFS. The context and motivation can be seen in cover
>>> letter of the RFC v1[1]. We also recorded a talk about this effort at LPC [3],
>>> if someone would like more context on this effort.
>>
>> Thank you.  This is a lot better.
>>
>> I'm still trying to understand your opinion on the contents of the
>> file_ra_state.  Is it supposed to be properly aligned at all times, or
>> do we work with it in the terms of "desired number of pages" and then
>> force it to conform to the minimum-block-size reality right at the end?
>> Because you seem to be doing both at various points.
> 
> Guess what, that's what I had been pondering, too.
> Each way has its benefits, I guess.
> 
> Question really is do we keep the readahead iterator in units of pages,
> and convert the result, or do we modify the readahead iterator to work
> on folios, and convert the inputs.
> 
> Doesn't really matter much, but we need to decide. The former is probably easier on the caller, and
> the latter is easier on the consumer.
> Take your pick; I really don't mind.
> 
> But we should document the result :-)
> 

Having experimented both approaches, I prefer the latter as it looks more consistent and
contain the changes to few functions.

> Cheers,
> 
> Hannes
>