This is because they reside within the C runtime library (libc.so), which was not (in this case) compiled with -pg and, hence, no profiling is gathered for any functions within this library.

这是因为这些函数都是在 C 运行时库（libc.so）中的，（在本例中）它们都没有使用 -pg 进行编译，因此就没有对这个库中的函数收集剖析信息。

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From Emsworth, PG Wodehouse on one occasion bicycled the 65 miles to London.

伍德豪斯骑自行车从埃姆斯·沃思出发，行程65英里到达伦敦。

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PG&E had previously signed a power purchase agreement with BrightSource in April 2008 for 500 megawatts with an option to buy another 400 megawatts.

PG&E与BrightSource曾在2008年4月签订了500兆瓦的电力购买协议，并拥有400兆瓦的优先购买权。

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But, like a lot of these films, this one has a parental guidance rating of "PG-13."

VOA: special.2011.06.20

Unlike most of the other outdoor cinemas mentioned here, this one is family-friendly with G- and PG-13-rated movies.

BBC: The best outdoor cinemas in Los Angeles

That compares with 24% for "Avengers" and is an impressive figure for a movie rated PG-13.

WSJ: Marvel's 'Iron Man 3' Takes in $175.3 Million at Box Office

When it comes to sex and nudity, Facebook is strictly PG-13, according to the guidelines.

FORBES: How Facebook Outsources Its Nudity Patrol