On Mon, Oct 10, 2016 at 10:46:27AM -0700, John Baldwin wrote: > On Monday, October 10, 2016 02:09:01 PM Slawa Olhovchenkov wrote: > > On Mon, Oct 03, 2016 at 11:15:44PM +0000, John Baldwin wrote: > > > > > Author: jhb > > > Date: Mon Oct 3 23:15:44 2016 > > > New Revision: 306661 > > > URL: https://svnweb.freebsd.org/changeset/base/306661 > > > > > > Log: > > > MFC 303405: Add support for zero-copy aio_write() on TOE sockets. > > > > > > AIO write requests for a TOE socket on a Chelsio T4+ adapter can now > > > DMA directly from the user-supplied buffer. This is implemented by > > > wiring the pages backing the user-supplied buffer and queueing special > > > mbufs backed by raw VM pages to the socket buffer. The TOE code > > > recognizes these special mbufs and builds a sglist from the VM page > > > array associated with the mbuf when queueing a work request to the TOE. > > > > > > Because these mbufs do not have an associated virtual address, m_data > > > is not valid. Thus, the AIO handler does not invoke sosend() directly > > > for these mbufs but instead inlines portions of sosend_generic() and > > > tcp_usr_send(). > > > > > > An aiotx_buffer structure is used to describe the user buffer (e.g. > > > it holds the array of VM pages and a reference to the AIO job). The > > > special mbufs reference this structure via m_ext. Note that a single > > > job might be split across multiple mbufs (e.g. if it is larger than > > > the socket buffer size). The 'ext_arg2' member of each mbuf gives an > > > offset relative to the backing aiotx_buffer. The AIO job associated > > > with an aiotx_buffer structure is completed when the last reference to > > > the structure is released. > > > > > > Zero-copy aio_write()'s for connections associated with a given > > > adapter can be enabled/disabled at runtime via the > > > 'dev.t[45]nex.N.toe.tx_zcopy' sysctl. > > > > > > Sponsored by: Chelsio Communications > > > > Do you have any public available application patches for support this? > > May be nginx? > > Applications need to use aio_read(), ideally with at least 2 buffers (so > queue two reads, then when a read completes, consume the data and do the > next read). I'm not sure nginx will find this but so useful as web servers > tend to send a lot more data than they receive. The only software I have > patched explicitly for this is netperf.
Hm, this is like only aio_read() on sokets give performance boost, not aio_write()? _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
