From: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
To: Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>, Ira Weiny <ira.weiny@intel.com>,
linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Subject: [PATCH 0/3] btrfs: Replace kmap() with kmap_local_page()
Date: Tue, 31 May 2022 16:53:32 +0200 [thread overview]
Message-ID: <20220531145335.13954-1-fmdefrancesco@gmail.com> (raw)
This is the first series of patches aimed towards the conversion of Btrfs
filesystem from the use of kmap() to kmap_local_page().
The use of kmap() is being deprecated in favor of kmap_local_page() where
it is feasible. With kmap_local_page() the mapping is per thread, CPU
local and not globally visible.
Therefore, use kmap_local_page() / kunmap_local() in Btrfs wherever the
mappings are per thread and not globally visible.
Tested on QEMU + KVM 32 bits VM with 4GB of RAM and HIGHMEM64G enabled.
tweed32:~ # uname -a
Linux tweed32 5.18.0-torvalds-debug-x86_32+ #2 SMP PREEMPT_DYNAMIC Tue \
May 31 15:20:07 CEST 2022 i686 athlon i386 GNU/Linux
tweed32:~ # btrfs check -p ~zoek/dev/btrfs.file
Opening filesystem to check...
Checking filesystem on /home/zoek/dev/btrfs.file
UUID: 897d65c5-1167-45b4-b811-2bfe74a320ca
[1/7] checking root items (0:00:00 elapsed, 1774 items checked)
[2/7] checking extents (0:00:00 elapsed, 135 items checked)
[3/7] checking free space tree (0:00:00 elapsed, 4 items checked)
[4/7] checking fs roots (0:00:00 elapsed, 104 items checked)
[5/7] checking csums (without verifying data) (0:00:00 elapsed, 205 items checked)
[6/7] checking root refs (0:00:00 elapsed, 3 items checked)
[7/7] checking quota groups skipped (not enabled on this FS)
found 47394816 bytes used, no error found
total csum bytes: 44268
total tree bytes: 2064384
total fs tree bytes: 1720320
total extent tree bytes: 180224
btree space waste bytes: 465350
file data blocks allocated: 45330432
referenced 45330432
Fabio M. De Francesco (3):
btrfs: Replace kmap() with kmap_local_page() in inode.c
btrfs: Replace kmap() with kmap_local_page() in lzo.c
btrfs: Replace kmap() with kmap_local_page() in zlib.c
fs/btrfs/inode.c | 6 +++---
fs/btrfs/lzo.c | 28 ++++++++++++----------------
fs/btrfs/zlib.c | 40 ++++++++++++++++++++--------------------
3 files changed, 35 insertions(+), 39 deletions(-)
--
2.36.1
next reply other threads:[~2022-05-31 14:53 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-31 14:53 Fabio M. De Francesco [this message]
2022-05-31 14:53 ` [PATCH 1/3] btrfs: Replace kmap() with kmap_local_page() in inode.c Fabio M. De Francesco
2022-05-31 15:46 ` Christoph Hellwig
2022-05-31 14:53 ` [PATCH 2/3] btrfs: Replace kmap() with kmap_local_page() in lzo.c Fabio M. De Francesco
2022-05-31 15:53 ` Christoph Hellwig
2022-05-31 14:53 ` [PATCH 3/3] btrfs: Replace kmap() with kmap_local_page() in zlib.c Fabio M. De Francesco
2022-05-31 15:53 ` Christoph Hellwig
2022-05-31 20:35 ` kernel test robot
2022-06-01 19:57 ` Fabio M. De Francesco
2022-06-06 12:11 ` Dan Carpenter
2022-06-01 13:25 ` [PATCH 0/3] btrfs: Replace kmap() with kmap_local_page() David Sterba
2022-06-02 16:22 ` Ira Weiny
2022-06-02 16:46 ` Matthew Wilcox
2022-06-02 18:01 ` Fabio M. De Francesco
2022-06-02 15:20 ` Christoph Hellwig
2022-06-02 15:55 ` Ira Weiny
2022-06-02 16:28 ` David Sterba
2022-06-05 15:11 ` Fabio M. De Francesco
2022-06-06 10:32 ` David Sterba
2022-06-06 14:32 ` Fabio M. De Francesco
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