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Kajol Jain 505d31650b powerpc/perf: Fix the threshold compare group constraint for power10
Thresh compare bits for a event is used to program thresh compare
field in Monitor Mode Control Register A (MMCRA: 8-18 bits for power10).
When scheduling events as a group, all events in that group should
match value in threshold bits. Otherwise event open for the sibling
events should fail. But in the current code, incase thresh compare bits are
not valid, we are not failing in group_constraint function which can result
in invalid group schduling.

Fix the issue by returning -1 incase event is threshold and threshold
compare value is not valid in group_constraint function.

Patch also fixes the p10_thresh_cmp_val function to return -1,
incase threshold bits are not valid and changes corresponding check in
is_thresh_cmp_valid function to return false only when the thresh_cmp
value is less then 0.

Thresh control bits in the event code is used to program thresh_ctl
field in Monitor Mode Control Register A (MMCRA: 48-55). In below example,
the scheduling of group events PM_MRK_INST_CMPL (3534401e0) and
PM_THRESH_MET (34340101ec) is expected to fail as both event
request different thresh control bits.

Result before the patch changes:

[command]# perf stat -e "{r35340401e0,r34340101ec}" sleep 1

 Performance counter stats for 'sleep 1':

             8,482      r35340401e0
                 0      r34340101ec

       1.001474838 seconds time elapsed

       0.001145000 seconds user
       0.000000000 seconds sys

Result after the patch changes:

[command]# perf stat -e "{r35340401e0,r34340101ec}" sleep 1

 Performance counter stats for 'sleep 1':

     <not counted>      r35340401e0
   <not supported>      r34340101ec

       1.001499607 seconds time elapsed

       0.000204000 seconds user
       0.000760000 seconds sys

Fixes: 82d2c16b35 ("powerpc/perf: Adds support for programming of Thresholding in P10")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220506061015.43916-1-kjain@linux.ibm.com
2022-05-22 15:58:29 +10:00
Documentation powerpc: Book3S 64-bit outline-only KASAN support 2022-05-22 15:58:29 +10:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch powerpc/perf: Fix the threshold compare group constraint for power10 2022-05-22 15:58:29 +10:00
block block: don't print I/O error warning for dead disks 2022-04-15 06:33:03 -06:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
drivers powerpc/powernv/vas: Assign real address to rx_fifo in vas_rx_win_attr 2022-05-22 15:58:27 +10:00
fs mm: Add len and flags parameters to arch_get_mmap_end() 2022-05-05 22:11:57 +10:00
include mm: Add len and flags parameters to arch_get_mmap_end() 2022-05-05 22:11:57 +10:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel - Fix a corner case when calculating sched runqueue variables 2022-04-24 13:28:06 -07:00
lib XArray: Disallow sibling entries of nodes 2022-04-22 15:35:40 -04:00
mm mm: Add len and flags parameters to arch_get_mmap_end() 2022-05-05 22:11:57 +10:00
net netlink: reset network and mac headers in netlink_dump() 2022-04-19 15:05:03 +02:00
samples dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
scripts hardening fixes for v5.18-rc3 2022-04-12 14:29:40 -10:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound ALSA: hda/realtek: Add quirk for Clevo NP70PNP 2022-04-21 21:23:47 +02:00
tools selftests/powerpc: Better reporting in spectre_v2 2022-05-22 15:58:28 +10:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt KVM: SEV: add cache flush to solve SEV cache incoherency issues 2022-04-21 15:41:00 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Vasily Averin's email address 2022-04-08 14:20:36 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2022-04-22 10:10:43 -07:00
Makefile Linux 5.18-rc4 2022-04-24 14:51:22 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.