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References: <20221121075237.127706-1-leo.yan@linaro.org>
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From:   Ian Rogers <irogers@google.com>
Date:   Mon, 21 Nov 2022 09:05:14 -0800
Message-ID: <CAP-5=fVHpzT1Q0U=e_svzQ2+a0iSoYppL8hRmOTAHZ0_nk2Z_g@mail.gmail.com>
Subject: Re: [PATCH v1 0/5] perf trace: Cleanup and remove unused bpf map
To:     Leo Yan <leo.yan@linaro.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-perf-users@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Sun, Nov 20, 2022 at 11:52 PM Leo Yan <leo.yan@linaro.org> wrote:
>
> The initial purpose of this series is to cleanup the unused bpf map
> 'syscalls' in the eBPF program augmented_raw_syscalls and perf trace
> tool.  The relality is perf trace tool initializes system call table
> based on map 'syscalls' and wrongly returns syscall pointer for
> non-existed system calls based on the previous initialization.
>
> So the patch set firstly addresses the issue for handling non-existed
> system calls, then it removes unused local variable and bpf map in
> augmented_raw_syscalls.c.
>
> Patch 01 is a minor refactoring to use macro to replace number, patch 02
> is to return error if a system call doesn't exist, especially when we
> cannot find corresponding trace point in sysfs node, patch 03 is to fix
> the issue that trace__syscall_info() returns a syscall pointer even the
> system call doesn't exist, the corrected result is to always return NULL
> pointer for non-existed system call.
>
> The last two patches remove the unused local variable and bpf map
> 'syscalls'.
>
> This patch set has been tested with mainline kernel on Arm64 Ampere
> Altra platform.
>
> Leo Yan (5):
>   perf trace: Use macro RAW_SYSCALL_ARGS_NUM to replace number
>   perf trace: Return error if a system call doesn't exist
>   perf trace: Handle failure when trace point folder is missed
>   perf augmented_raw_syscalls: Remove unused variable 'syscall'
>   perf trace: Remove unused bpf map 'syscalls'


Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

>  tools/perf/builtin-trace.c                    | 131 +++---------------
>  .../examples/bpf/augmented_raw_syscalls.c     |  18 ---
>  2 files changed, 18 insertions(+), 131 deletions(-)
>
> --
> 2.34.1
>