Hardware can use either size, it's a built time option.
64K is standard and is what we use by default and 99% of distros use.
4K is more compatible with desktop applications and GPU drivers,
which often assume 4K page size.
Problem from switching page sizes on reboot:
btrfs and swaps break, other filesystems like ext4 may become
unmountable, sepending on direction of switch 4K <-> 64K.
Our installcd provides both kernel options, so users can choose which
one to boot.
Planned consumers of this flag:
sys-kernel/gentoo-kernel
sys-kernel/gentoo-kernel-bin ( in the future )
sys-kernel/vanilla-kernel
dev-util/google-perftools
any other application that has a build time switch to optimize for or
set page size.
Also can be used by applications that are known to be broken with
specific page size.
Mesa and amdgpu drivers used to have some problems in the past, but it
was fixed, however broken apps still exist.
Signed-off-by: Georgy Yakovlev <
gyakovlev@gentoo.org>
---
profiles/arch/powerpc/ppc64/make.defaults | 6 +++++-
profiles/base/make.defaults | 4 ++--
profiles/desc/ppc_pagesize.desc | 5 +++++
profiles/embedded/make.defaults | 4 ++--
4 files changed, 14 insertions(+), 5 deletions(-)
create mode 100644 profiles/desc/ppc_pagesize.desc
diff --git a/profiles/arch/powerpc/ppc64/make.defaults b/profiles/arch/powerpc/ppc64/make.defaults
index ff2526a2530..6555ec277b7 100644
--- a/profiles/arch/powerpc/ppc64/make.defaults
+++ b/profiles/arch/powerpc/ppc64/make.defaults
@@ -1,41 +1,45 @@
-# Copyright 1999-2021 Gentoo Authors
+# Copyright 1999-2022 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
# All extra USE/etc should be specified in sub-profiles.
# DO NOT POLLUTE USE ON THIS PROFILE.
+# Georgy Yakovlev <
gyakovlev@gentoo.org> (2022-01-04)
+# Unhide PPC specific USE_EXPANDs.
+USE_EXPAND_HIDDEN="-PPC_PAGESIZE"
+
ARCH="ppc64"
ACCEPT_KEYWORDS="${ARCH}"
CHOST="powerp