Messages in this thread | | | Date | Tue, 16 Nov 2021 20:51:18 +0800 | Subject | Re: [PATCH v2 2/2] scripts: ftrace - move the nop-processing in ftrace_init to compile time | From | Yinan Liu <> |
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在 2021/11/16 下午4:10, Peter Zijlstra 写道: > On Tue, Nov 16, 2021 at 10:49:42AM +0800, Yinan Liu wrote: >> In some business scenarios, GCC versions are so old that >> optimizations in ftrace cannot be completed, such as >> -mrecord-mcount and -mnop-mcount. The recordmCount in the >> kernel is actually used. In this case, ftrace_init will >> consume a period of time, usually around 9~12ms. Do nop >> substitution in recordmcount.c to speed up ftrace_init. > > I really don't buy this.. if you can build a fresh kernel, you can > install a fresh gcc too -- and if you care about performance that's a > very good idea anyway. > Thanks! You are right. We should get rid of the burden.
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