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Vlastimil Babka 6c6c47b063 mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()
We would like to replace call_rcu() users with kfree_rcu() where the
existing callback is just a kmem_cache_free(). However this causes
issues when the cache can be destroyed (such as due to module unload).

Currently such modules should be issuing rcu_barrier() before
kmem_cache_destroy() to have their call_rcu() callbacks processed first.
This barrier is however not sufficient for kfree_rcu() in flight due
to the batching introduced by a35d16905e ("rcu: Add basic support for
kfree_rcu() batching").

This is not a problem for kmalloc caches which are never destroyed, but
since removing SLOB, kfree_rcu() is allowed also for any other cache,
that might be destroyed.

In order not to complicate the API, put the responsibility for handling
outstanding kfree_rcu() in kmem_cache_destroy() itself. Use the newly
introduced kvfree_rcu_barrier() to wait before destroying the cache.
This is similar to how we issue rcu_barrier() for SLAB_TYPESAFE_BY_RCU
caches, but has to be done earlier, as the latter only needs to wait for
the empty slab pages to finish freeing, and not objects from the slab.

Users of call_rcu() with arbitrary callbacks should still issue
rcu_barrier() before destroying the cache and unloading the module, as
kvfree_rcu_barrier() is not a superset of rcu_barrier() and the
callbacks may be invoking module code or performing other actions that
are necessary for a successful unload.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
arch s390 updates for 6.11-rc5 2024-08-25 12:05:23 +12:00
block block: Read max write zeroes once for __blkdev_issue_write_zeroes() 2024-08-19 09:48:59 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto crypto: testmgr - generate power-of-2 lengths more often 2024-07-13 11:50:28 +12:00
Documentation workqueue: Fixes for v6.11-rc4 2024-08-24 10:35:57 +08:00
drivers s390 updates for 6.11-rc5 2024-08-25 12:05:23 +12:00
fs bcachefs fixes for 6.11-rc5, v2 2024-08-25 17:20:48 +12:00
include rcu/kvfree: Add kvfree_rcu_barrier() API 2024-08-27 14:12:51 +02:00
init Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
io_uring io_uring/kbuf: sanitize peek buffer setup 2024-08-21 07:16:38 -06:00
ipc sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kernel rcu/kvfree: Add kvfree_rcu_barrier() API 2024-08-27 14:12:51 +02:00
lib bcachefs fixes for 6.11-rc4 2024-08-17 09:46:10 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy() 2024-08-27 14:12:51 +02:00
net NFS Client Bugfixes for Linux 6.11-rc 2024-08-24 09:03:25 +08:00
rust Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
samples treewide: remove unnecessary <linux/version.h> inclusion 2024-08-12 18:36:44 +09:00
scripts Kbuild fixes for v6.11 (2nd) 2024-08-23 07:43:15 +08:00
security KEYS: trusted: dcp: fix leak of blob encryption key 2024-08-15 22:01:14 +03:00
sound Kbuild fixes for v6.11 (2nd) 2024-08-23 07:43:15 +08:00
tools Including fixes from bluetooth and netfilter. 2024-08-23 07:47:01 +08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) 2024-08-14 12:28:24 -04:00
.clang-format Docs: Move clang-format from process/ to dev-tools/ 2024-06-26 16:36:00 -06:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: add script and target to generate pacman package 2024-07-22 01:24:22 +09:00
.mailmap mailmap: update entry for David Heidelberg 2024-08-07 18:33:56 -07:00
.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 tracing: Update of MAINTAINERS and CREDITS file 2024-07-18 14:08:42 -07:00
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 SCSI fixes on 20240824 2024-08-25 12:00:16 +12:00
Makefile Linux 6.11-rc5 2024-08-25 19:07:11 +12:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.