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From: Max Kellermann <max.kellermann@ionos.com>
To: idryomov@gmail.com, amarkuze@redhat.com,
	ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Max Kellermann <max.kellermann@ionos.com>
Subject: [PATCH 00/12] fs/ceph: optimize struct layouts
Date: Fri, 12 Jun 2026 18:51:52 +0200	[thread overview]
Message-ID: <20260612165204.86137-1-max.kellermann@ionos.com> (raw)

This patch set aims to reduce the memory usage of the Ceph filesystems
by optimizing the layout of structs, most importantly struct
ceph_inode_info:

- use `bool` instead of `int` for booelans
- use `u32` instead of `u64` where possible
- reorder fields to eliminate padding holes
- eliminate redundant fields

Without this patch set, ceph_inode_info looks like this with pahole:

  /* size: 1456, cachelines: 23, members: 78 */
  /* sum members: 1424, holes: 8, sum holes: 32 */
  /* member types with holes: 4, total: 4 */

With this patch set, struct ceph_inode_info got smaller by 96 bytes:

  /* size: 1360, cachelines: 22, members: 75 */
  /* member types with holes: 2, total: 2 */

Max Kellermann (12):
  fs/ceph/super: remove unused field `i_cap_migration_resv`
  fs/ceph/super: make field `i_truncate_pagecache_size` optional
  include/ceph/ceph_fs.h: convert `pool_id` to u32
  fs/ceph/super.h: convert ceph_inode_xattr fields to `bool`
  fs/ceph/super.h: convert ceph_cap_snap.writing fields to `bool`
  fs/ceph: consistently use `u32` for `time_warp_seq`
  fs/ceph/super: reorder fields to eliminate padding holes
  fs/ceph: remove i_truncate_mutex, use i_fragtree_mutex for both
  fs/ceph/super.h: add `const` to helpers
  fs/ceph/super.h: add helper ceph_in_snap()
  fs/ceph: use ceph_vino() etc. instead of accessing i_vino directly
  fs/ceph: remove redundant inode number from ceph_inode_info

 fs/ceph/acl.c                |   2 +-
 fs/ceph/addr.c               |  23 ++++----
 fs/ceph/cache.c              |   4 +-
 fs/ceph/caps.c               |   8 +--
 fs/ceph/dir.c                |  20 +++----
 fs/ceph/export.c             |   8 +--
 fs/ceph/file.c               |  28 +++++-----
 fs/ceph/inode.c              |  38 ++++++++-----
 fs/ceph/mds_client.c         |  12 ++---
 fs/ceph/mds_client.h         |   2 +-
 fs/ceph/quota.c              |   6 +--
 fs/ceph/snap.c               |   8 +--
 fs/ceph/super.h              | 102 +++++++++++++++++++++++++----------
 fs/ceph/util.c               |   8 +--
 fs/ceph/xattr.c              |  18 +++----
 include/linux/ceph/ceph_fs.h |   2 +-
 16 files changed, 171 insertions(+), 118 deletions(-)

-- 
2.47.3


             reply	other threads:[~2026-06-12 16:52 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-12 16:51 Max Kellermann [this message]
2026-06-12 16:51 ` [PATCH 01/12] fs/ceph/super: remove unused field `i_cap_migration_resv` Max Kellermann
2026-06-12 16:51 ` [PATCH 02/12] fs/ceph/super: make field `i_truncate_pagecache_size` optional Max Kellermann
2026-06-12 16:51 ` [PATCH 03/12] include/ceph/ceph_fs.h: convert `pool_id` to u32 Max Kellermann
2026-06-12 16:51 ` [PATCH 04/12] fs/ceph/super.h: convert ceph_inode_xattr fields to `bool` Max Kellermann
2026-06-12 16:51 ` [PATCH 05/12] fs/ceph/super.h: convert ceph_cap_snap.writing " Max Kellermann
2026-06-12 16:51 ` [PATCH 06/12] fs/ceph: consistently use `u32` for `time_warp_seq` Max Kellermann
2026-06-12 16:51 ` [PATCH 07/12] fs/ceph/super: reorder fields to eliminate padding holes Max Kellermann
2026-06-12 16:52 ` [PATCH 08/12] fs/ceph: remove i_truncate_mutex, use i_fragtree_mutex for both Max Kellermann
2026-06-12 16:52 ` [PATCH 09/12] fs/ceph/super.h: add `const` to helpers Max Kellermann
2026-06-12 16:52 ` [PATCH 10/12] fs/ceph/super.h: add helper ceph_in_snap() Max Kellermann
2026-06-12 16:52 ` [PATCH 11/12] fs/ceph: use ceph_vino() etc. instead of accessing i_vino directly Max Kellermann
2026-06-12 16:52 ` [PATCH 12/12] fs/ceph: remove redundant inode number from ceph_inode_info Max Kellermann

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