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cbb72a3c19
If the CPU assigned to the xgene PMU is taken offline, then subsequent
perf invocations on the PMU will fail:
# echo 0 > /sys/devices/system/cpu/cpu0/online
# perf stat -a -e l3c0/cycle-count/,l3c0/write/ sleep 1
Error:
The sys_perf_event_open() syscall returned with 19 (No such device) for event (l3c0/cycle-count/).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
This patch implements a hotplug notifier in the xgene PMU driver so that
the PMU context is migrated to another online CPU should its assigned
CPU disappear.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Hoan Tran <hoan.tran@amperecomputing.com>
[will: Made naming of new cpuhp_state enum entry consistent]
Signed-off-by: Will Deacon <will.deacon@arm.com>
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.