Hiralo added a comment. In D90010#2355432 <https://reviews.llvm.org/D90010#2355432>, @dblaikie wrote:
> Looks like you might be able to do something like > "llvm::errs().setBuffered()" ? Do we need to set it for each function using llvm:errs() (e.g. here printStats() ) OR can it be set once for entire clang-tidy ? >> In D90010#2352627 <https://reviews.llvm.org/D90010#2352627>, @dblaikie wrote: >> >>> (the patch description doesn't explain any specific motivation either - >>> whether it's performance (runtime? memory usage? etc?) or something else, >>> and how the performance aspect has been quantified) >> >> The motivation is to avoid 7 write calls which helps in large build system >> and easy on NFS! > > Sorry, I meant "why does any of this matter" I take it you mean "because 7 > write calls are slower than 1 in <this situation> by <this much > time/percentage>" - do you have rough data/description of the situation where > the speed of printing error messages matters and by how much does it matter? > (I think it would be good to have this data no matter the solution - be it > explicit or built-in buffering) No worries. Thanks for your valuable reviews. For example, consider clang-tidy running on 10,000 files... we expect to have minimal number of write calls. With the code-as-is makes 10,000 * 7 = 70,000 stderr write calls with small small chunk of strings!!! With proposed changes OR with llvm::errs().setBuffered() set we will see only 10,000 legitimate stderr write calls :) Thank you. -Hiral Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D90010/new/ https://reviews.llvm.org/D90010 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
