5 ms·
What's stopping those 4 patches from being upstreamed? What advantages or disadvantages am I getting from them?
by voltagex_ 4y ago
What's stopping those 4 patches from being upstreamed?
What advantages or disadvantages am I getting from them?
- miffe 4y agoLooking at it it seems to require avx2. And use the "m" mode for fopen(), which I have no idea what it does, it's not in any documentation I can find.
- aslatter 4y agoFrom my fopen(2) docs: m (since glibc 2.3) Attempt to access the file using mmap(2), rather than I/O system calls (read(2), write(2)). Currently, use of mmap(2) is attempted only for a file opened for reading.
- eklitzke 4y agoI'm very skeptical that this actually makes things faster. For one, zstd is definitely going to be CPU bound rather than I/O bound. But even if it wasn't, there shouldn't be a performance benefit to reading a file sequentially using mmap compared to reading it sequentially using read, which you can easily verify yourself by writing a small program that just reads files both ways.
- dikei 4y agoI think for clear linux, it might be for memory saving in constraint devices rather than for speed optimization.
- dikei 4y agoWhen a distro maintains patches, it's mostly down to either: * Change default value for some parameters, that can't be upstream due to compatibility reasons. * Change build flag / macro for optimization and/or workaround compiler bugs.