From: Namhyung Kim <namhyung@kernel.org>
To: Kim Phillips <kim.phillips@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@redhat.com>, Jiri Olsa <jolsa@kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>, David Ahern <dsahern@gmail.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
kernel-team@lge.com
Subject: Re: [PATCH] Revert "perf machine: Fix paranoid check in machine__set_kernel_mmap()"
Date: Thu, 12 Apr 2018 10:57:56 +0900 [thread overview]
Message-ID: <20180412015756.GA6962@sejong> (raw)
In-Reply-To: <20180411192940.de8143a80bd9e5d98d87f6ec@arm.com>
On Wed, Apr 11, 2018 at 07:29:40PM -0500, Kim Phillips wrote:
> On Thu, 12 Apr 2018 08:31:09 +0900
> Namhyung Kim <namhyung@kernel.org> wrote:
>
> > Hello,
>
> Hi,
>
> > On Wed, Apr 11, 2018 at 06:07:52PM -0500, Kim Phillips wrote:
> > > ---
> > > It's not clear to me what the specific intent of the original commit
> > > was, thus the revert.
> >
> > Hmm.. maybe your kernel map has non-zero start and zero end. I
>
> On x86, the first line in /proc/kallsyms is:
>
> 0000000000000000 A irq_stack_union
>
> On arm64, it's:
>
> ffff200008080000 t _head
>
> Another arm64 box has:
>
> ffff000008080000 t _head
>
> (neither have RANDOMIZE_BASE set FWIW)
>
> > thought it was just from an old or invalid data. But now I think that
>
> It would be good to know what that was, yes.
>
> > overflow can create it.. could you please show me the mmap event?
> >
> > $ perf script --show-mmap-events
>
> Here you go:
>
> swapper 0 [000] 0.000000: PERF_RECORD_MMAP -1/0: [0xffff200008080000(0xdffff7f7ffff) @ 0xffff200008080000]: x [kernel.kallsyms]_text
0xffff200008080000
+ 0xdffff7f7ffff
--------------------
0xffffffffffffffff
So it should have ~0ULL of the 'end' already. I don't know why it
caused the problem.. Was it from the `perf.good`?
> swapper 0 [000] 0.000000: PERF_RECORD_MMAP -1/0: [0xffff2000021e0000(0x18000) @ 0]: x /lib/modules/4.16.0+/kernel/drivers/bus/arm-ccn.ko
Hmm.. also it seems arm64 loads modules under the kernel. Then the
fixup logic in machine__create_kernel_maps() won't work. Also as we
don't use the map_groups__fixup_end() anymore I think it's ok just
checking the end address.
Thanks,
Namhyung
next prev parent reply other threads:[~2018-04-12 1:58 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-15 12:26 [PATCHv3 0/9] perf tool: Assorted fixes Jiri Olsa
2018-02-15 12:26 ` [PATCH 1/9] tools lib symbol: Skip non-address kallsyms line Jiri Olsa
2018-02-17 11:24 ` [tip:perf/core] " tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 2/9] perf tools: Check if we read regular file in dso__load Jiri Olsa
2018-02-17 11:24 ` [tip:perf/core] perf symbols: Check if we read regular file in dso__load() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 3/9] perf tools: Free root_dir in machine__init error path Jiri Olsa
2018-02-17 11:25 ` [tip:perf/core] perf machine: Free root_dir in machine__init() " tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 4/9] perf tools: Move kernel mmap name into struct machine Jiri Olsa
2018-02-17 11:25 ` [tip:perf/core] perf machine: " tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 5/9] perf tools: Generalize machine__set_kernel_mmap function Jiri Olsa
2018-02-17 11:26 ` [tip:perf/core] perf machine: Generalize machine__set_kernel_mmap() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 6/9] perf tools: Don't search for active kernel start in __machine__create_kernel_maps Jiri Olsa
2018-02-17 11:26 ` [tip:perf/core] perf machine: " tip-bot for Jiri Olsa
2018-02-19 2:20 ` [PATCH 6/9] perf tools: " Namhyung Kim
2018-02-19 10:01 ` Jiri Olsa
2018-02-19 10:19 ` Namhyung Kim
2018-02-19 10:49 ` Jiri Olsa
2018-02-19 12:18 ` Arnaldo Carvalho de Melo
2018-04-11 23:07 ` [PATCH] Revert "perf machine: Fix paranoid check in machine__set_kernel_mmap()" Kim Phillips
2018-04-11 23:31 ` Namhyung Kim
2018-04-12 0:29 ` Kim Phillips
2018-04-12 1:57 ` Namhyung Kim [this message]
2018-04-13 0:09 ` Kim Phillips
2018-04-13 7:36 ` Namhyung Kim
2018-02-21 10:25 ` [tip:perf/core] perf machine: Fix paranoid check in machine__set_kernel_mmap() tip-bot for Namhyung Kim
2018-02-19 12:21 ` [PATCH 6/9] perf tools: Don't search for active kernel start in __machine__create_kernel_maps Arnaldo Carvalho de Melo
2018-02-19 14:05 ` Namhyung Kim
2018-02-15 12:26 ` [PATCH 7/9] perf tools: Remove machine__load_kallsyms function Jiri Olsa
2018-02-17 11:27 ` [tip:perf/core] perf machine: Remove machine__load_kallsyms() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 8/9] perf tools: Do not create kernel maps in sample__resolve Jiri Olsa
2018-02-17 11:27 ` [tip:perf/core] perf tools: Do not create kernel maps in sample__resolve() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 9/9] perf tests: Use arch__compare_symbol_names to compare symbols Jiri Olsa
2018-02-15 14:27 ` Arnaldo Carvalho de Melo
2018-02-15 14:48 ` Naveen N. Rao
2018-02-15 15:10 ` Arnaldo Carvalho de Melo
2018-02-17 11:28 ` [tip:perf/core] " tip-bot for Jiri Olsa
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