kernel/linux.git/tools/perf/bench/mem-functions.c, branch linux-7.1.y

perf tools: Make more global variables static

2026-04-09T02:21:04+00:00

`make check` will run sparse on the perf code base. A frequent warning is "warning: symbol '...' was not declared. Should it be static?" Go through and make global definitions without declarations static. In some cases it is deliberate due to dlsym accessing the symbol, this change doesn't clean up the missing declarations for perf test suites. Sometimes things can opportunistically be made const. Making somethings static exposed unused functions warnings, so restructuring of ifdefs was necessary for that. These changes reduce the size of the perf binary by 568 bytes. Committer notes: Refreshed the patch, the original one fell thru the cracks, updated the size reduction. Remove the trace-event-scripting.c changes, break the build, noticed with container builds and with sashiko: https://sashiko.dev/#/patchset/20260401215306.2152898-1-acme%40kernel.org Also make two variables static to address another sashiko review comment: https://sashiko.dev/#/patchset/20260402001740.2220481-1-acme%40kernel.org Signed-off-by: Ian Rogers Acked-by: Ankur Arora Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Athira Rajeev Cc: Guo Ren Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Leo Yan Cc: Masami Hiramatsu Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Yujie Liu Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf bench: Add -t/--threads option to perf bench mem mmap

2026-02-26T18:54:12+00:00

So that it can measure overhead of mmap_lock and/or per-VMA lock contention. $ perf bench mem mmap -f demand -l 1000 -t 1 # Running 'mem/mmap' benchmark: # function 'demand' (Demand loaded mmap()) # Copying 1MB bytes ... 2.786858 GB/sec $ perf bench mem mmap -f demand -l 1000 -t 2 # Running 'mem/mmap' benchmark: # function 'demand' (Demand loaded mmap()) # Copying 1MB bytes ... 1.624468 GB/sec/thread ( +- 0.30% ) $ perf bench mem mmap -f demand -l 1000 -t 3 # Running 'mem/mmap' benchmark: # function 'demand' (Demand loaded mmap()) # Copying 1MB bytes ... 1.493068 GB/sec/thread ( +- 0.15% ) $ perf bench mem mmap -f demand -l 1000 -t 4 # Running 'mem/mmap' benchmark: # function 'demand' (Demand loaded mmap()) # Copying 1MB bytes ... 1.006087 GB/sec/thread ( +- 0.41% ) Reviewed-by: Ankur Arora Reviewed-by: James Clark Signed-off-by: Namhyung Kim

perf bench mem: Add mmap() workloads

2025-09-19T15:43:59+00:00

Add two mmap() workloads: one that eagerly populates a region and another that demand faults it in. The intent is to probe the memory subsytem performance incurred by mmap(). $ perf bench mem mmap -s 4gb -p 4kb -l 10 -f populate # Running 'mem/mmap' benchmark: # function 'populate' (Eagerly populated map()) # Copying 4gb bytes ... 1.811691 GB/sec $ perf bench mem mmap -s 4gb -p 2mb -l 10 -f populate # Running 'mem/mmap' benchmark: # function 'populate' (Eagerly populated mmap()) # Copying 4gb bytes ... 12.272017 GB/sec $ perf bench mem mmap -s 4gb -p 1gb -l 10 -f populate # Running 'mem/mmap' benchmark: # function 'populate' (Eagerly populated mmap()) # Copying 4gb bytes ... 17.085927 GB/sec Signed-off-by: Ankur Arora Tested-by: Arnaldo Carvalho de Melo Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Refactor mem_options

2025-09-19T15:43:49+00:00

Split mem benchmark options into common and memset/memcpy specific. Reviewed-by: Namhyung Kim Signed-off-by: Ankur Arora Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Allow chunking on a memory region

2025-09-19T15:43:38+00:00

There can be a significant gap in memset/memcpy performance depending on the size of the region being operated on. With chunk-size=4kb: $ echo madvise > /sys/kernel/mm/transparent_hugepage/enabled $ perf bench mem memset -p 4kb -k 4kb -s 4gb -l 10 -f x86-64-stosq # Running 'mem/memset' benchmark: # function 'x86-64-stosq' (movsq-based memset() in arch/x86/lib/memset_64.S) # Copying 4gb bytes ... 13.011655 GB/sec With chunk-size=1gb: $ echo madvise > /sys/kernel/mm/transparent_hugepage/enabled $ perf bench mem memset -p 4kb -k 1gb -s 4gb -l 10 -f x86-64-stosq # Running 'mem/memset' benchmark: # function 'x86-64-stosq' (movsq-based memset() in arch/x86/lib/memset_64.S) # Copying 4gb bytes ... 21.936355 GB/sec So, allow the user to specify the chunk-size. The default value is identical to the total size of the region, which preserves current behaviour. Reviewed-by: Namhyung Kim Signed-off-by: Ankur Arora Tested-by: Arnaldo Carvalho de Melo Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Allow mapping of hugepages

2025-09-19T15:43:26+00:00

Page sizes that can be selected: 4KB, 2MB, 1GB. Both the reservation and node from which hugepages are allocated from are expected to be addressed by the user. An example of page-size selection: $ perf bench mem memset -s 4gb -p 2mb # Running 'mem/memset' benchmark: # function 'default' (Default memset() provided by glibc) # Copying 4gb bytes ... 14.919194 GB/sec # function 'x86-64-unrolled' (unrolled memset() in arch/x86/lib/memset_64.S) # Copying 4gb bytes ... 11.514503 GB/sec # function 'x86-64-stosq' (movsq-based memset() in arch/x86/lib/memset_64.S) # Copying 4gb bytes ... 12.600568 GB/sec Signed-off-by: Ankur Arora Tested-by: Arnaldo Carvalho de Melo Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Switch from zalloc() to mmap()

2025-09-19T15:43:12+00:00

Using mmap() ensures that the buffer is always aligned at a fixed boundary. Switch to that to remove one source of variability. Since we always want to read/write from the allocated buffers map with pagetables pre-populated. Reviewed-by: Namhyung Kim Signed-off-by: Ankur Arora Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Pull out init/fini logic

2025-09-19T15:43:01+00:00

No functional change. Reviewed-by: Namhyung Kim Signed-off-by: Ankur Arora Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Move mem op parameters into a structure

2025-09-19T15:42:50+00:00

Move benchmark function parameters in struct bench_params. Reviewed-by: Namhyung Kim Signed-off-by: Ankur Arora Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20250917152418.4077386-4-ankur.a.arora@oracle.com Signed-off-by: Arnaldo Carvalho de Melo

perf bench mem: Defer type munging of size to float

2025-09-19T15:42:40+00:00

Do type conversion to double at the point of use. Reviewed-by: Namhyung Kim Signed-off-by: Ankur Arora Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20250917152418.4077386-3-ankur.a.arora@oracle.com Signed-off-by: Arnaldo Carvalho de Melo