Messages in this thread | | | Date | Mon, 7 Feb 2022 11:31:17 +0800 | From | Leo Yan <> | Subject | Re: [PATCH v1] perf synthetic-events: Return error if procfs isn't mounted for PID namespaces |
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On Sun, Feb 06, 2022 at 08:46:37AM -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, Feb 04, 2022 at 08:48:49PM +0800, Leo Yan escreveu: > > On Fri, Jan 07, 2022 at 02:27:57PM +0000, James Clark wrote: > > > On 24/12/2021 12:40, Leo Yan wrote: > > > > For perf recording, it retrieves process info by iterating nodes in proc > > > > fs. If we run perf in a non-root PID namespace with command: > > > > > > > > # unshare --fork --pid perf record -e cycles -a -- test_program > > > > > > > > ... in this case, unshare command creates a child PID namespace and > > > > launches perf tool in it, but the issue is the proc fs is not mounted > > > > for the non-root PID namespace, this leads to the perf tool gathering > > > > process info from its parent PID namespace. > > > > > > > > > > I had some concerns that this would prevent use of perf in docker, but docker > > > does mount /proc so it is still working. And you've added a warning about how > > > to fix the unshare command so I think this is ok. > > > > > > Reviewed-by: James Clark <james.clark@arm.com> > > > > Thanks a lot for review, James. > > > > Arnaldo, Jiri, could you take a look for this patch? Thanks! > > Looks sane, there was discussion, a detailed set of steps to reproduce > the problem was provided, thanks, applied.
Thank you, Arnaldo!
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