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Mike Snitzer 99659d2345 nfs: avoid i_lock contention in nfs_clear_invalid_mapping
[ Upstream commit 867da60d46 ]

Multi-threaded buffered reads to the same file exposed significant
inode spinlock contention in nfs_clear_invalid_mapping().

Eliminate this spinlock contention by checking flags without locking,
instead using smp_rmb and smp_load_acquire accordingly, but then take
spinlock and double-check these inode flags.

Also refactor nfs_set_cache_invalid() slightly to use
smp_store_release() to pair with nfs_clear_invalid_mapping()'s
smp_load_acquire().

While this fix is beneficial for all multi-threaded buffered reads
issued by an NFS client, this issue was identified in the context of
surprisingly low LOCALIO performance with 4K multi-threaded buffered
read IO.  This fix dramatically speeds up LOCALIO performance:

before: read: IOPS=1583k, BW=6182MiB/s (6482MB/s)(121GiB/20002msec)
after:  read: IOPS=3046k, BW=11.6GiB/s (12.5GB/s)(232GiB/20001msec)

Fixes: 17dfeb9113 ("NFS: Fix races in nfs_revalidate_mapping")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-14 13:15:11 +01:00
arch ARM: dts: rockchip: Fix the realtek audio codec on rk3036-kylin 2024-11-14 13:15:10 +01:00
block block: fix sanity checks in blk_rq_map_user_bvec 2024-11-08 16:26:45 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: simd - Do not call crypto_alloc_tfm during registration 2024-10-17 15:21:39 +02:00
Documentation ASoC: dt-bindings: davinci-mcasp: Fix interrupt properties 2024-11-01 01:56:05 +01:00
drivers platform/x86/amd/pmc: Detect when STB is not available 2024-11-14 13:15:10 +01:00
fs nfs: avoid i_lock contention in nfs_clear_invalid_mapping 2024-11-14 13:15:11 +01:00
include NFSv3: handle out-of-order write replies. 2024-11-14 13:15:10 +01:00
init rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT 2024-08-29 17:30:32 +02:00
io_uring io_uring: always lock __io_cqring_overflow_flush 2024-11-08 16:26:47 +01:00
ipc sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table) 2024-08-11 12:35:51 +02:00
kernel cgroup/bpf: use a dedicated workqueue for cgroup bpf destruction 2024-11-08 16:26:45 +01:00
lib maple_tree: correct tree corruption on spanning store 2024-10-22 15:56:44 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm migrate_pages_batch: fix statistics for longterm pin retry 2024-11-08 16:26:48 +01:00
net sunrpc: handle -ENOTCONN in xs_tcp_setup_socket() 2024-11-14 13:15:10 +01:00
rust rust: macros: provide correct provenance when constructing THIS_MODULE 2024-10-17 15:22:24 +02:00
samples bpf: Replace bpf_lpm_trie_key 0-length array with flexible array 2024-08-29 17:30:22 +02:00
scripts kconfig: qconf: fix buffer overflow in debug links 2024-10-17 15:22:03 +02:00
security selinux: improve error checking in sel_write_load() 2024-11-01 01:56:07 +01:00
sound ALSA: hda/realtek: Fix headset mic on TUXEDO Stellaris 16 Gen6 mb1 2024-11-08 16:26:46 +01:00
tools usbip: tools: Fix detach_port() invalid port error path 2024-11-08 16:26:44 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() 2024-06-27 13:46:21 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Remove *.orig pattern from .gitignore 2024-10-17 15:21:15 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add leah to 6.1 MAINTAINERS file 2024-05-17 11:56:16 +02:00
Makefile Linux 6.1.116 2024-11-08 16:26:48 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.