Zhengjun Xing
7a32d17fb7
commit96fd2e89fbupstream. The user recently report a perf issue in the ICX platform, when test by perf event “uncore_imc_x/cas_count_write”,the write bandwidth is always very small (only 0.38MB/s), it is caused by the wrong "umask" for the "cas_count_write" event. When double-checking, find "cas_count_read" also is wrong. The public document for ICX uncore: 3rd Gen Intel® Xeon® Processor Scalable Family, Codename Ice Lake,Uncore Performance Monitoring Reference Manual, Revision 1.00, May 2021 On 2.4.7, it defines Unit Masks for CAS_COUNT: RD b00001111 WR b00110000 So corrected both "cas_count_read" and "cas_count_write" for ICX. Old settings: hswep_uncore_imc_events INTEL_UNCORE_EVENT_DESC(cas_count_read, "event=0x04,umask=0x03") INTEL_UNCORE_EVENT_DESC(cas_count_write, "event=0x04,umask=0x0c") New settings: snr_uncore_imc_events INTEL_UNCORE_EVENT_DESC(cas_count_read, "event=0x04,umask=0x0f") INTEL_UNCORE_EVENT_DESC(cas_count_write, "event=0x04,umask=0x30") Fixes:2b3b76b5ec("perf/x86/intel/uncore: Add Ice Lake server uncore support") Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20211223144826.841267-1-zhengjun.xing@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.