Received-SPF: pass (google.com: domain of linux-kernel+bounces-108540-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Date: Wed, 20 Mar 2024 07:28:24 +0000
In-Reply-To: <021efce7-1e40-43a6-9bfd-0d968bfcd5a8@kylinos.cn>
Precedence: bulk
Mime-Version: 1.0
References: <20240126075547.1521556-1-mengfanhui@kylinos.cn>
 <Zfp7Y9x2iOE_prpp@google.com> <021efce7-1e40-43a6-9bfd-0d968bfcd5a8@kylinos.cn>
Message-ID: <ZfqQGGfKStVxDwYT@google.com>
Subject: Re: [PATCH] config/mips: support zswap function
From: Yosry Ahmed <yosryahmed@google.com>
To: mengfanhui <mengfanhui@kylinos.cn>
Cc: tsbogend@alpha.franken.de, geert+renesas@glider.be, 
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, 
	hannes@cmpxchg.org, nphamcs@gmail.com, chengming.zhou@linux.dev
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable

On Wed, Mar 20, 2024 at 02:44:21PM +0800, mengfanhui wrote:
> Zswap and zsmalloc are compression methods, and kernel configuration can =
be configured simultaneously.
> zbud is an algorithm, and users can use that method if they want to use i=
t.It won't affect each other.

Zswap compressed swapped out pages in-memory. To store those compressed
pages, it uses one of three allocators that implement the zpool API:
zbud, z3fold, and zsmalloc. In that sense, zsmalloc is comparable to
zbud, not zswap. I suspect you are mixing up zsmalloc and zram.

Anyway, zsmalloc is the default allocator and should be better for
almost all use cases. So unless you have a very good reason to use zbud
over zsmalloc, please do not use zbud. We are trying to deprecate zbud
and z3fold.

>=20
> =E5=9C=A8 2024/3/20 14:00, Yosry Ahmed =E5=86=99=E9=81=93:
> > On Fri, Jan 26, 2024 at 03:55:47PM +0800, mengfanhui wrote:
> >> Solution /sys/module/zswap/parameters/enabled attribute node
> >> does not exist issue=EF=BC=8Chandle zpool zbud initialization failed,
> >> open CONFIG_ZSWAP CONFIG_ZPOOL CONFIG_ZBUD configuration,manual
> >> zswap function by /sys/module/zswap/parameters/enabled file
> >>
> >> Signed-off-by: mengfanhui <mengfanhui@kylinos.cn>
> >> ---
> >>  arch/mips/configs/generic_defconfig | 3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/arch/mips/configs/generic_defconfig b/arch/mips/configs/g=
eneric_defconfig
> >> index 071e2205c7ed..14884df392f4 100644
> >> --- a/arch/mips/configs/generic_defconfig
> >> +++ b/arch/mips/configs/generic_defconfig
> >> @@ -13,6 +13,9 @@ CONFIG_CGROUP_DEVICE=3Dy
> >>  CONFIG_CGROUP_CPUACCT=3Dy
> >>  CONFIG_NAMESPACES=3Dy
> >>  CONFIG_USER_NS=3Dy
> >> +CONFIG_ZSWAP=3Dy
> >> +CONFIG_ZPOOL=3Dy
> >> +CONFIG_ZBUD=3Dy
> >=20
> > Any reason for choosing zbud over zsmalloc, the default zswap allocator=
?
> >=20
> >>  CONFIG_SCHED_AUTOGROUP=3Dy
> >>  CONFIG_BLK_DEV_INITRD=3Dy
> >>  CONFIG_BPF_SYSCALL=3Dy
> >> --=20
> >> 2.25.1
> >>