29c11aa808
The test case creates 4 threads and then pins these 4 threads in CPU 0. These 4 threads will run different bpf program through bpf_prog_test_run_opts() and these bpf program will use bpf_obj_new() and bpf_obj_drop() to allocate and free local kptrs concurrently. Under preemptible kernel, bpf_obj_new() and bpf_obj_drop() may preempt each other, bpf_obj_new() may return NULL and the test will fail before applying these fixes as shown below: test_preempted_bpf_ma_op:PASS:open_and_load 0 nsec test_preempted_bpf_ma_op:PASS:attach 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:FAIL:ENOMEM unexpected ENOMEM: got TRUE #168 preempted_bpf_ma_op:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230901111954.1804721-4-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.