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[bpf,v2,0/3] bpf: two fixes for bpf iterators

Message ID 20200818222309.2181236-1-yhs@fb.com
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Series bpf: two fixes for bpf iterators | expand

Message

Yonghong Song Aug. 18, 2020, 10:23 p.m. UTC 
Patch #1 fixed a rcu stall warning when traversing large number
of tasks/files without overflowing seq_file buffer. The method
is to control the number of visited objects in bpf_seq_read()
so all bpf iterators will benefit.

Patch #2 calculated tid properly in a namespace in order to avoid
visiting the name task multiple times.

Patch #3 handled read() error code EAGAIN properly in bpftool
bpf_iter userspace code to collect pids. The change is needed
due to Patch #1.

Yonghong Song (3):
  bpf: fix a rcu_sched stall issue with bpf task/task_file iterator
  bpf: avoid visit same object multiple times
  bpftool: handle EAGAIN error code properly in pids collection

 kernel/bpf/bpf_iter.c    | 15 ++++++++++++++-
 kernel/bpf/task_iter.c   |  3 ++-
 tools/bpf/bpftool/pids.c |  2 ++
 3 files changed, 18 insertions(+), 2 deletions(-)