Re: sendfile+zerocopy: fairly sexy (nothing to do with ECN)

[David S. Miller]

David Lang writes:
 > right, assuming that there is enough sendfile() benifit to overcome the
 > write() penalty from the stuff that can't be cached or sent from a file.
 > 
 > my question was basicly are there enough places where sendfile would
 > actually be used to make it a net gain.

There are non-performance issues as well (really, all of these points
have been mentioned in this thread btw).  One is that since paged
SKBs use only single-order page allocations, the memory allocation
subsystem is stressed less than the current scheme where SLAB
allocates multi-order pages to satisfy allocations of linear SKB data
buffers.

This has consequences and benefits system wide.

Later,
David S. Miller
[e-mail]