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Subject: Re: [PATCH] perf tools: add aarch64 registers to --user-regs
To:     Alexandre Truong <alexandre.truong@arm.com>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org
Cc:     John Garry <john.garry@huawei.com>, Leo Yan <leo.yan@linaro.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>
References: <20201127153923.26717-1-alexandre.truong@arm.com>
From:   James Clark <james.clark@arm.com>
Message-ID: <cd0592be-68d2-c88d-ff18-05f7d3ba8cc2@arm.com>
Date:   Mon, 30 Nov 2020 17:54:57 +0200
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On 27/11/2020 17:39, Alexandre Truong wrote:
> Previously, this command returns no help message on aarch64:
> 
>   -> ./perf record --user-regs=?
> 
>   available registers:
>   Usage: perf record [<options>] [<command>]
>       or: perf record [<options>] -- <command> [<options>]
> 
> With this change, the registers are listed.
> 
>   -> ./perf record --user-regs=?
> 
>   available registers: x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15 x16 x17 x18 x19 x20 x21 x22 x23 x24 x25 x26 x27 x28 x29 lr sp pc
> 
> It's also now possible to record subsets of registers on aarch64:
> 
>   -> ./perf record --user-regs=x4,x5 ls
>   -> ./perf report --dump-raw-trace
> 
>   12801163749305260 0xc70 [0x40]: PERF_RECORD_SAMPLE(IP, 0x2): 51956/51956: 0xffffaa6571f0 period: 145785 addr: 0
>   ... user regs: mask 0x30 ABI 64-bit
>   .... x4    0x000000000000006c
>   .... x5    0x0000001001000001
>    ... thread: ls:51956
>     ...... dso: /usr/lib64/ld-2.17.so
> 

Checked that the registers can be listed with =? and that recording different combinations of registers works as expected.

Tested-by: James Clark <james.clark@arm.com>