Song Liu ced47e30ab bpf: runqslower: Use task local storage ... Replace hashtab with task local storage in runqslower. This improves the performance of these BPF programs. The following table summarizes average runtime of these programs, in nanoseconds: task-local hash-prealloc hash-no-prealloc handle__sched_wakeup 125 340 3124 handle__sched_wakeup_new 2812 1510 2998 handle__sched_switch 151 208 991 Note that, task local storage gives better performance than hashtab for handle__sched_wakeup and handle__sched_switch. On the other hand, for handle__sched_wakeup_new, task local storage is slower than hashtab with prealloc. This is because handle__sched_wakeup_new accesses the data for the first time, so it has to allocate the data for task local storage. Once the initial allocation is done, subsequent accesses, as those in handle__sched_wakeup, are much faster with task local storage. If we disable hashtab prealloc, task local storage is much faster for all 3 functions. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210225234319.336131-7-songliubraving@fb.com		2021-02-26 11:51:48 -08:00
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.gitignore	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
Makefile	bpf: runqslower: Prefer using local vmlimux to generate vmlinux.h	2021-02-26 11:51:48 -08:00
runqslower.bpf.c	bpf: runqslower: Use task local storage	2021-02-26 11:51:48 -08:00
runqslower.c	tools/runqslower: Use consistent include paths for libbpf	2020-01-20 16:37:45 -08:00
runqslower.h