From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: [PATCH RFC 0/7] mm: PG_reserved cleanups and documentation Date: Wed, 5 Dec 2018 13:28:44 +0100 Message-ID: <20181205122851.5891-1-david@redhat.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-mediatek@lists.infradead.org, David Hildenbrand , Albert Ou , Alexander Duyck , Andrew Morton , Anthony Yznaga , Arnd Bergmann , Benjamin Herrenschmidt , Bhupesh Sharma , Catalin Marinas , Christophe Leroy , Dan Williams , Dave Kleikamp , David Airlie List-Id: linux-mediatek@lists.infradead.org I was recently going over all users of PG_reserved. Short story: it is difficult and sometimes not really clear if setting/checking for PG_reserved is only a relict from the past. Easy to break things. I had way more cleanups in this series inititally, but some architectures take PG_reserved as a way to apply a different caching strategy (for MMIO pages). So I decided to only include the most obvious changes (that are less likely to break something). So let's see if the documentation update for PG_reserved I crafted actually covers most cases or if there is plenty more. Most notably, for device memory we can hopefully soon stop setting it PG_reserved I only briefly tested this on s390x. David Hildenbrand (7): agp: efficeon: no need to set PG_reserved on GATT tables s390/vdso: don't clear PG_reserved powerpc/vdso: don't clear PG_reserved riscv/vdso: don't clear PG_reserved m68k/mm: use __ClearPageReserved() arm64: kexec: no need to ClearPageReserved() mm: better document PG_reserved arch/arm64/kernel/machine_kexec.c | 1 - arch/m68k/mm/memory.c | 2 +- arch/powerpc/kernel/vdso.c | 2 -- arch/riscv/kernel/vdso.c | 1 - arch/s390/kernel/vdso.c | 2 -- drivers/char/agp/efficeon-agp.c | 2 -- include/linux/page-flags.h | 18 ++++++++++++++++-- 7 files changed, 17 insertions(+), 11 deletions(-) -- 2.17.2