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author | Huichun Feng <foxhoundsk.tw@gmail.com> | 2024-06-10 01:37:28 +0800 |
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committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2024-06-10 09:37:52 +0200 |
commit | 7f1e45f4ae7671550e15354ef87194bccd99ecec (patch) | |
tree | 626bee31c35346e223e15a5cdb91d733a704825e /tools/perf/scripts/python/task-analyzer.py | |
parent | 54a687cd49e3625819f24e17655346c85f498cbc (diff) |
docs: gpio: prefer pread(2) for interrupt reading
In legacy sysfs GPIO, when using poll(2) on the sysfs GPIO value for
state change awaiting, a subsequent read(2) is required for consuming
the event, which the doc recommends the use of lseek(2) or
close-and-reopen to reset the file offset afterwards.
The recommendations however, require at least 2 syscalls to consume
the event. Gladly, use of pread(2) require only 1 syscall for the
consumption. Let's advertise this usage by prioritizing its placement.
Signed-off-by: Huichun Feng <foxhoundsk.tw@gmail.com>
Link: https://lore.kernel.org/r/20240609173728.2950808-1-foxhoundsk.tw@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'tools/perf/scripts/python/task-analyzer.py')
0 files changed, 0 insertions, 0 deletions