linux-kernel - Re: [PATCH v5 00/21] mm/zsmalloc: add zpdesc memory descriptor for zswap.zpool

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Message-ID: <20240815031314.GA12106@google.com>
Date: Thu, 15 Aug 2024 12:13:14 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Alex Shi <seakeel@...il.com>
Cc: Matthew Wilcox <willy@...radead.org>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Yosry Ahmed <yosryahmed@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>, alexs@...nel.org,
	Vitaly Wool <vitaly.wool@...sulko.com>,
	Miaohe Lin <linmiaohe@...wei.com>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, minchan@...nel.org, david@...hat.com,
	42.hyeyoo@...il.com, nphamcs@...il.com
Subject: Re: [PATCH v5 00/21] mm/zsmalloc: add zpdesc memory descriptor for
 zswap.zpool

On (24/08/09 10:32), Alex Shi wrote:
[..]
> >> and we "chain" zpdesc-s to form a zspage, and make each of them point to
> >> a corresponding struct page (memdesc -> *page), then it'll resemble current
> >> zsmalloc and should work for everyone? I also assume for zspdesc-s zsmalloc
> >> will need to maintain a dedicated kmem_cache?
> > Right, we could do that.  Each memdesc has to be a multiple of 16 bytes,
> > sp we'd be doing something like allocating 32 bytes for each page.
> > Is there really 32 bytes of information that we want to store for
> > each page?  Or could we store all of the information in (a somewhat
> > larger) zspage?  Assuming we allocate 3 pages per zspage, if we allocate
> > an extra 64 bytes in the zspage, we've saved 32 bytes per zspage.
> 
> Thanks for the suggestions! Yes, it's a good direction we could try after this
> patchset.

Alex, may I ask what exactly you will "try"?