Draft
Conversation
While working on pointer tracking changes I found it necessary to
update expected log messages in align.c series of tests.
As a preliminary step, migrate these tests to test_loader framework.
The tests in question load BPF program and check if expected log is
produced, the log is specified as:
.matches = {
...
{4, "R3", "32"},
...
}
Where:
- '4' is an *instruction number* (contrary to the field name in
struct bpf_reg_match).
- 'R3' is the name of the register to check.
- '32' is the value expected for this register.
Mimic the same logic using __msg macro.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260211051310.2782558-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding uprobe syscall feature detection that will be used in following changes. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding support to detect nop,nop5 instructions combo for usdt probe by checking on probe's following nop5 instruction. When the nop,nop5 combo is detected together with uprobe syscall, we can place the probe on top of nop5 and get it optimized. [1] https://github.com/libbpf/usdt Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Syncing latest usdt.h change [1]. Now that we have nop5 optimization support in kernel, let's emit nop,nop5 for usdt probe. We leave it up to the library to use desirable nop instruction. [1] libbpf/usdt@c9865d1 Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding test that attaches bpf program on usdt probe in 2 scenarios; - attach program on top of usdt_1, which is single nop instruction, so the probe stays on nop instruction and is not optimized. - attach program on top of usdt_2 which is probe defined on top of nop,nop5 combo, so the probe is placed on top of nop5 and is optimized. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding usdt trigger bench for usdt: trig-usdt-nop - usdt on top of nop1 instruction trig-usdt-nop5 - usdt on top of nop1/nop5 combo Adding it to benchs/run_bench_uprobes.sh script. Example run on x86_64 kernel with uprobe syscall: # ./benchs/run_bench_uprobes.sh usermode-count : 152.507 ± 0.098M/s syscall-count : 14.309 ± 0.093M/s uprobe-nop : 3.190 ± 0.012M/s uprobe-push : 3.057 ± 0.004M/s uprobe-ret : 1.095 ± 0.009M/s uprobe-nop5 : 7.305 ± 0.034M/s uretprobe-nop : 2.175 ± 0.005M/s uretprobe-push : 2.109 ± 0.003M/s uretprobe-ret : 0.945 ± 0.002M/s uretprobe-nop5 : 3.530 ± 0.006M/s usdt-nop : 3.235 ± 0.008M/s <-- added usdt-nop5 : 7.511 ± 0.045M/s <-- added Signed-off-by: Jiri Olsa <jolsa@kernel.org>
olsajiri
force-pushed
the
usdt_nop_ci
branch
from
8f5fd26 to
10aa558
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
2 times, most recently
from
a4a9811 to
2650068
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
No description provided.