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Robin Murphy a428eb4b99 Partially revert "perf/arm-cmn: Optimise DTC counter accesses"
It turns out the optimisation implemented by commit 4f2c3872dd is
totally broken, since all the places that consume hw->dtcs_used for
events other than cycle count are still not expecting it to be sparsely
populated, and fail to read all the relevant DTC counters correctly if
so.

If implemented correctly, the optimisation potentially saves up to 3
register reads per event update, which is reasonably significant for
events targeting a single node, but still not worth a massive amount of
additional code complexity overall. Getting it right within the current
design looks a fair bit more involved than it was ever intended to be,
so let's just make a functional revert which restores the old behaviour
while still backporting easily.

Fixes: 4f2c3872dd ("perf/arm-cmn: Optimise DTC counter accesses")
Reported-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b41bb4ed7283c3d8400ce5cf5e6ec94915e6750f.1674498637.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-01-26 13:55:38 +00:00
arch arm64: Fix build with CC=clang, CONFIG_FTRACE=y and CONFIG_STACK_TRACER=y 2023-01-09 15:59:42 +00:00
block treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto This update includes the following changes: 2022-12-14 12:31:09 -08:00
Documentation arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption 2023-01-06 17:14:55 +00:00
drivers Partially revert "perf/arm-cmn: Optimise DTC counter accesses" 2023-01-26 13:55:38 +00:00
fs elfcore: Add a cprm parameter to elf_core_extra_{phdrs,data_size} 2023-01-05 15:12:12 +00:00
include firmware/psci: Fix MEM_PROTECT_RANGE function numbers 2023-01-06 17:12:39 +00:00
init Kbuild updates for v6.2 2022-12-19 12:33:32 -06:00
io_uring io_uring/net: fix cleanup after recycle 2022-12-19 08:28:28 -07:00
ipc Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
kernel kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
lib test_maple_tree: add test for mas_spanning_rebalance() on insufficient data 2022-12-21 14:31:52 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm hugetlb: really allocate vma lock for all sharable vmas 2022-12-21 14:31:52 -08:00
net treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
rust rust: types: add Opaque type 2022-12-04 01:59:16 +01:00
samples Char/Misc driver changes for 6.2-rc1 2022-12-16 03:49:24 -08:00
scripts modernize use of grep in coccicheck 2022-12-23 13:56:41 -08:00
security kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
sound treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
tools perf tools fixes and improvements for v6.2: 2nd batch 2022-12-22 11:07:29 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt ARM64: 2022-12-15 11:12:21 -08:00
.clang-format iommufd for 6.2 2022-12-14 09:15:43 -08:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes
.gitignore kbuild: Cleanup DT Overlay intermediate files as appropriate 2022-11-18 14:45:30 -06:00
.mailmap Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -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: zram: zsmalloc: Add an additional co-maintainer 2022-12-15 16:37:49 -08:00
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 io_uring-6.2-2022-12-19 2022-12-21 16:28:25 -08:00
Makefile Linux 6.2-rc1 2022-12-25 13:41:39 -08:00
README

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.