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From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Magnus Damm <magnus.damm@gmail.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	linux-renesas-soc@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH LOCAL] arm64: renesas: defconfig: Enable Transparent Hugepage madvise
Date: Mon, 21 Dec 2020 09:36:23 +0100	[thread overview]
Message-ID: <20201221083623.4156421-1-geert+renesas@glider.be> (raw)

Enabling Transparent Hugepage always can increase the memory footprint
of applications without a guaranteed benefit.

Documentation/admin-guide/mm/transhuge.rst says:

    Embedded systems should enable hugepages only inside madvise regions
    to eliminate any risk of wasting any precious byte of memory and to
    only run faster.

Hence enable Transparent Hugepage madvise instead, which will only
provide a performance improvement benefit to the applications using
madvise(MADV_HUGEPAGE), but it won't risk to increase the memory
footprint of applications without a guaranteed benefit.

Suggested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Not intended for upstream merge; to be applied to the
topic/renesas-defconfig only.

Perhaps this should be changed in arch/arm64/configs/defconfig, too?
Perhaps the default should be changed in mm/Kconfig instead?
---
 arch/arm64/configs/renesas_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/renesas_defconfig b/arch/arm64/configs/renesas_defconfig
index 71a6cb34ca89229c..f641a2675d0a425b 100644
--- a/arch/arm64/configs/renesas_defconfig
+++ b/arch/arm64/configs/renesas_defconfig
@@ -75,6 +75,7 @@ CONFIG_BLK_DEV_INTEGRITY=y
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_KSM=y
 CONFIG_TRANSPARENT_HUGEPAGE=y
+CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y
 CONFIG_CMA=y
 CONFIG_NET=y
 CONFIG_PACKET=y
-- 
2.25.1


             reply	other threads:[~2020-12-21  8:37 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-21  8:36 Geert Uytterhoeven [this message]
2020-12-23 23:22 ` [PATCH LOCAL] arm64: renesas: defconfig: Enable Transparent Hugepage madvise Kuninori Morimoto

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