Messages in this thread | | | Subject | Re: [PATCH v6 1/3] perf: add PERF_RECORD_NAMESPACES to include namespaces related info | From | Hari Bathini <> | Date | Mon, 20 Feb 2017 09:46:03 +0530 |
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Hi Eric,
On Thursday 16 February 2017 04:55 PM, Eric W. Biederman wrote: >> +/* >> + * The maximum size of the name of each namespace >> + */ >> +#define NS_NAME_SIZE 8 >> + >> +struct perf_ns_link_info { >> + char name[NS_NAME_SIZE]; >> + __u64 dev; >> + __u64 ino; >> +}; > Ugh. I missed the name the first time around. > > That really looks like useless clutter. You already know the index so > the name doesn't add any information, so unless I am missing something > that name will just slow down the perf kernel implementation with > useless work. > > The userspace reader can have the information just as reliably by > looking at the index and indexing into a table. > > The set of namespaces changes slowly enough that this is not likely to > be a problem in practice. Especially as perf is released with the > kernel. > > Plus who knows how long the name of the next namespace is going to be. >
Agreed. Will drop name field from the structure and use an indexing table to get names in userspace..
Thanks Hari
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