linux-kernel - perf record -e branch-misses ls

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <08994540-d132-6e49-f6a0-82d8dfd1f3f0@windriver.com>
Date:   Wed, 8 Mar 2023 15:56:41 +0800
From:   wangxiaolei <xiaolei.wang@...driver.com>
To:     will@...nel.org, mark.rutland@....com, peterz@...radead.org,
        mingo@...hat.com, acme@...nel.org,
        alexander.shishkin@...ux.intel.com, jolsa@...nel.org,
        namhyung@...nel.org, irogers@...gle.com, linux@...linux.org.uk
Cc:     linux-arm-kernel@...ts.infradead.org,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: perf record -e branch-misses ls > /dev/null

hi

When I use the perf tool on nxp-imx6sx, the CPU is armv7 cortex-A9 to 
test, I execute the perf record -e branch-misses ls > /dev/null command, 
but the perf report result is indeed:
perf report
Error:
The perf.data data has no samples!
# To display the perf.data header info, please use 
--header/--header-only options.

root@...-imx6:~# perf list hardware

List of pre-defined events (to be used in -e):

    branch-instructions OR branches [Hardware event]
    branch-misses [Hardware event]
    bus-cycles [Hardware event]
    cache-misses [Hardware event]
    cache-references [Hardware event]
    cpu-cycles OR cycles [Hardware event]
    instructions [Hardware event]

And not only this one hardware event, only cycles are working normally 
in the following supported hardware time, other hardware events are not 
interrupted and reported, and the value in the read PMXEVCNTR register 
is always -1, and the PMCR register E, bit[0 ] it will be written to 0 
before reading the PMXEVCNTR register. I don’t know if the value in the 
PMXEVCNTR register is always -1 for this reason. Does anyone have any 
good suggestions for debugging this problem?


thanks

xiaolei