On 07/17/2010 11:45 PM, Steven Dake wrote:
On 07/16/2010 10:46 PM, Jeff Garzik wrote:
chunkd: remove sendfile(2) zero-copy support
chunkd will be soon checksumming data in main memory. That removes
the utility of a zero-copy interface which bypasses the on-heap
data requirement.
Signed-off-by: Jeff Garzik<jgarzik@xxxxxxxxxx>
May be able to use vmsplice with sendfile (if linux is only target
platform). Haven't tried it myself, but the operations look interesting
at achieving zero copy with sockets from memory addresses.
Even though the man pages say "only for pipes", this syscall definitely
works with TCP. The big question: is it actually faster than
read()+write() ?
Years ago, I experimented with using some fancy new Linux-specific
syscalls in a from-scratch implementation of cp(1). It turned out that
read()+write() was faster than other methods.
That was file->file copying. It's probably worth investigating
vmsplice() for our file->checksum->TCP case, definitely.
Jeff
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