3638e44542
Perf bench epoll fails as below when attempted to run on on a powerpc system: ./perf bench epoll wait Running 'epoll/wait' benchmark: Run summary [PID 627653]: 79 threads monitoring on 64 file-descriptors for 8 secs. perf: pthread_create: No such file or directory In the setup where this perf bench was ran, difference was that partition had 640 CPU's, but not all CPUs were online. 80 CPUs were online. While creating threads and using epoll_wait , code sets the affinity using cpumask. The cpumask size used is 80 which is picked from "nrcpus = perf_cpu_map__nr(cpu)". Here the benchmark reports fail while setting affinity for cpu number which is greater than 80 or higher, because it attempts to set a bit position which is not allocated on the cpumask. Fix this by changing the size of cpumask to number of possible cpus and not the number of online cpus. Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Reviewed-by: Ian Rogers <irogers@google.com> Tested-by: Disha Goel <disgoel@linux.ibm.com> Cc: akanksha@linux.ibm.com Cc: kjain@linux.ibm.com Cc: maddy@linux.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240607044354.82225-2-atrajeev@linux.vnet.ibm.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 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.