No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Athira Rajeev 49e38713fa powerpc/perf: Record counter overflow always if SAMPLE_IP is unset
[ Upstream commit d137845c973147a22622cc76c7b0bc16f6206323 ]

While sampling for marked events, currently we record the sample only
if the SIAR valid bit of Sampled Instruction Event Register (SIER) is
set. SIAR_VALID bit is used for fetching the instruction address from
Sampled Instruction Address Register(SIAR). But there are some
usecases, where the user is interested only in the PMU stats at each
counter overflow and the exact IP of the overflow event is not
required. Dropping SIAR invalid samples will fail to record some of
the counter overflows in such cases.

Example of such usecase is dumping the PMU stats (event counts) after
some regular amount of instructions/events from the userspace (ex: via
ptrace). Here counter overflow is indicated to userspace via signal
handler, and captured by monitoring and enabling I/O signaling on the
event file descriptor. In these cases, we expect to get
sample/overflow indication after each specified sample_period.

Perf event attribute will not have PERF_SAMPLE_IP set in the
sample_type if exact IP of the overflow event is not requested. So
while profiling if SAMPLE_IP is not set, just record the counter
overflow irrespective of SIAR_VALID check.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Reflow comment and if formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1612516492-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:03:42 +01:00
arch powerpc/perf: Record counter overflow always if SAMPLE_IP is unset 2021-03-17 17:03:42 +01:00
block blk-settings: align max_sectors on "logical_block_size" boundary 2021-03-04 10:26:40 +01:00
certs certs: Fix blacklist flag type confusion 2021-03-04 10:26:29 +01:00
crypto crypto: tcrypt - avoid signed overflow in byte count 2021-03-07 12:20:46 +01:00
Documentation sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output 2021-03-07 12:20:48 +01:00
drivers spi: stm32: make spurious and overrun interrupts visible 2021-03-17 17:03:42 +01:00
fs udf: fix silent AED tagLocation corruption 2021-03-17 17:03:41 +01:00
include media: rc: compile rc-cec.c into rc-core 2021-03-17 17:03:40 +01:00
init fgraph: Initialize tracing_graph_pause at task creation 2021-02-10 09:25:29 +01:00
ipc
kernel sched/features: Fix hrtick reprogramming 2021-03-07 12:20:47 +01:00
lib udp: fix skb_copy_and_csum_datagram with odd segment sizes 2021-02-17 10:35:19 +01:00
LICENSES
mm Revert "mm, slub: consider rest of partial list if acquire_slab() fails" 2021-03-17 17:03:34 +01:00
net net: qrtr: fix error return code of qrtr_sendmsg() 2021-03-17 17:03:36 +01:00
samples samples, bpf: Add missing munmap in xdpsock 2021-03-17 17:03:33 +01:00
scripts ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcount 2021-03-09 11:09:39 +01:00
security smackfs: restrict bytes count in smackfs write functions 2021-03-07 12:20:42 +01:00
sound ASoC: Intel: bytcr_rt5640: Add quirk for ARCHOS Cesium 140 2021-03-11 14:06:50 +01:00
tools perf traceevent: Ensure read cmdlines are null terminated. 2021-03-17 17:03:37 +01:00
usr
virt KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() 2021-02-26 10:10:28 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.105 2021-03-11 14:06:51 +01:00
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.