| ced47e30 | 25-Feb-2021 |
Song Liu <[email protected]> |
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
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 <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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| 2d9393fe | 10-Nov-2020 |
Jean-Philippe Brucker <[email protected]> |
tools/runqslower: Build bpftool using HOSTCC
When cross building runqslower for an other architecture, the
intermediate bpftool used to generate a skeleton must be built using the
host toolchain. Pa
tools/runqslower: Build bpftool using HOSTCC
When cross building runqslower for an other architecture, the
intermediate bpftool used to generate a skeleton must be built using the
host toolchain. Pass HOSTCC and HOSTLD, defined in Makefile.include, to
the bpftool Makefile.
Signed-off-by: Jean-Philippe Brucker <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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| 85e59344 | 10-Nov-2020 |
Jean-Philippe Brucker <[email protected]> |
tools/runqslower: Enable out-of-tree build
Enable out-of-tree build for runqslower. Only set OUTPUT=.output if it
wasn't already set by the user.
Signed-off-by: Jean-Philippe Brucker <jean-philippe
tools/runqslower: Enable out-of-tree build
Enable out-of-tree build for runqslower. Only set OUTPUT=.output if it
wasn't already set by the user.
Signed-off-by: Jean-Philippe Brucker <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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