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Atish Patra <atishp@rivosinc.com> says: This series contains 3 fixes out of which the first one is a new fix for invalid event data reported in lkml[2]. The last two are v3 of Samuel's patch[1]. I added the RB/TB/Fixes tag and moved 1 unrelated change to its own patch. I also changed an error message in kvm vcpu_pmu from pr_err to pr_debug to avoid redundant failure error messages generated due to the boot time quering of events implemented in the patch[1] Here is the original cover letter for the patch[1] Before this patch: $ perf list hw List of pre-defined events (to be used in -e or -M): branch-instructions OR branches [Hardware event] branch-misses [Hardware event] bus-cycles [Hardware event] cache-misses [Hardware event] cache-references [Hardware event] cpu-cycles OR cycles [Hardware event] instructions [Hardware event] ref-cycles [Hardware event] stalled-cycles-backend OR idle-cycles-backend [Hardware event] stalled-cycles-frontend OR idle-cycles-frontend [Hardware event] $ perf stat -ddd true Performance counter stats for 'true': 4.36 msec task-clock # 0.744 CPUs utilized 1 context-switches # 229.325 /sec 0 cpu-migrations # 0.000 /sec 38 page-faults # 8.714 K/sec 4,375,694 cycles # 1.003 GHz (60.64%) 728,945 instructions # 0.17 insn per cycle 79,199 branches # 18.162 M/sec 17,709 branch-misses # 22.36% of all branches 181,734 L1-dcache-loads # 41.676 M/sec 5,547 L1-dcache-load-misses # 3.05% of all L1-dcache accesses <not counted> LLC-loads (0.00%) <not counted> LLC-load-misses (0.00%) <not counted> L1-icache-loads (0.00%) <not counted> L1-icache-load-misses (0.00%) <not counted> dTLB-loads (0.00%) <not counted> dTLB-load-misses (0.00%) <not counted> iTLB-loads (0.00%) <not counted> iTLB-load-misses (0.00%) <not counted> L1-dcache-prefetches (0.00%) <not counted> L1-dcache-prefetch-misses (0.00%) 0.005860375 seconds time elapsed 0.000000000 seconds user 0.010383000 seconds sys After this patch: $ perf list hw List of pre-defined events (to be used in -e or -M): branch-instructions OR branches [Hardware event] branch-misses [Hardware event] cache-misses [Hardware event] cache-references [Hardware event] cpu-cycles OR cycles [Hardware event] instructions [Hardware event] $ perf stat -ddd true Performance counter stats for 'true': 5.16 msec task-clock # 0.848 CPUs utilized 1 context-switches # 193.817 /sec 0 cpu-migrations # 0.000 /sec 37 page-faults # 7.171 K/sec 5,183,625 cycles # 1.005 GHz 961,696 instructions # 0.19 insn per cycle 85,853 branches # 16.640 M/sec 20,462 branch-misses # 23.83% of all branches 243,545 L1-dcache-loads # 47.203 M/sec 5,974 L1-dcache-load-misses # 2.45% of all L1-dcache accesses <not supported> LLC-loads <not supported> LLC-load-misses <not supported> L1-icache-loads <not supported> L1-icache-load-misses <not supported> dTLB-loads 19,619 dTLB-load-misses <not supported> iTLB-loads 6,831 iTLB-load-misses <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 0.006085625 seconds time elapsed 0.000000000 seconds user 0.013022000 seconds sys [1] https://lore.kernel.org/linux-riscv/20240418014652.1143466-1-samuel.holland@sifive.com/ [2] https://lore.kernel.org/all/CC51D53B-846C-4D81-86FC-FBF969D0A0D6@pku.edu.cn/ * b4-shazam-merge: perf: RISC-V: Check standard event availability drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus drivers/perf: riscv: Do not update the event data if uptodate Link: https://lore.kernel.org/r/20240628-misc_perf_fixes-v4-0-e01cfddcf035@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.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.