On Fri, 7 Dec 2007, David Miller wrote: > > Also I could end up being performance limited by SHA, it's not very > well tuned on Sparc. It's been on my TODO list to code up the crypto > unit support for Niagara-2 in the kernel, then work with Herbert Xu on > the userland interfaces to take advantage of that in things like > libssl. Even a better C/asm version would probably improve GIT > performance a bit. I doubt yu can use the hardware support. Kernel-only hw support is inherently broken for any sane user-space usage, the setup costs are just way way too high. To be useful, crypto engines need to support direct user space access (ie a regular instruction, with all state being held in normal registers that get saved/restored by the kernel). > Is SHA a significant portion of the compute during these repacks? > I should run oprofile... SHA1 is almost totally insignificant on x86. It hardly shows up. But we have a good optimized version there. zlib tends to be a lot more noticeable (especially the uncompression: it may be faster than compression, but it's done _so_ much more that it totally dominates). Linus - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
