| From: |
| "Ritesh Harjani (IBM)" <ritesh.list-AT-gmail.com> |
| To: |
| linux-mm-AT-kvack.org |
| Subject: |
| [RFC 0/4] mm, swap: Enable THP SWAP for PowerPC Book3S64 |
| Date: |
| Tue, 09 Jun 2026 18:49:30 +0530 |
| Message-ID: |
| <cover.1781000840.git.ritesh.list@gmail.com> |
| Cc: |
| Madhavan Srinivasan <maddy-AT-linux.ibm.com>, Michael Ellerman <mpe-AT-ellerman.id.au>, Nicholas Piggin <npiggin-AT-gmail.com>, Christophe Leroy <chleroy-AT-kernel.org>, Andrew Morton <akpm-AT-linux-foundation.org>, Chris Li <chrisl-AT-kernel.org>, Kairui Song <kasong-AT-tencent.com>, Kemeng Shi <shikemeng-AT-huaweicloud.com>, Nhat Pham <nphamcs-AT-gmail.com>, Baoquan He <baoquan.he-AT-linux.dev>, Barry Song <baohua-AT-kernel.org>, Youngjun Park <youngjun.park-AT-lge.com>, David Hildenbrand <david-AT-kernel.org>, linuxppc-dev-AT-lists.ozlabs.org, linux-kernel-AT-vger.kernel.org, Sayali Patil <sayalip-AT-linux.ibm.com>, "Ritesh Harjani (IBM)" <ritesh.list-AT-gmail.com> |
| Archive-link: |
| Article |
On PowerPC Book3S64, MMU is selected at runtime, so macros like PMD_SHIFT are
effectively runtime variables in the Book3S64 code. THP swap code uses these
macros for e.g. to size some of its array data structures based on PMD_ORDER.
This patch series makes that usage dependent on the runtime variable.
Sayali did some performance runs of this on Book3S64 with Radix and it gives
40-50% performance improvement. We also plan to run it with Hash, will soon
update the results.
Note that this patch series is based out of linux-next (next-20260608).
Ritesh Harjani (IBM) (4):
include/linux/swap.h: Remove unused leftovers
mm, swap: make SWAPFILE_CLUSTER runtime
mm, swap: make SWAP_NR_ORDERS runtime
powerpc: Kconfig: Enable THP_SWAP on Book3S64
arch/powerpc/platforms/Kconfig.cputype | 1 +
include/linux/swap.h | 17 +---
mm/swap.h | 5 +-
mm/swap_table.h | 6 +-
mm/swapfile.c | 132 ++++++++++++++++++-------
5 files changed, 106 insertions(+), 55 deletions(-)
--
2.39.5
