linux/net/decnet
Linus Torvalds a11e1d432b Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL
The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 10:40:47 -07:00
..
netfilter netfilter: nf_hook_ops structs can be const 2017-07-31 19:10:44 +02:00
af_decnet.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
dn_dev.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
dn_fib.c net: use rtnl_register_module where needed 2017-12-04 11:32:39 -05:00
dn_neigh.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
dn_nsp_in.c net: decnet: dn_nsp_in: use swap macro in dn_nsp_rx_packet 2017-11-01 12:05:49 +09:00
dn_nsp_out.c net: decnet: dn_nsp_out: use swap macro in dn_mk_ack_header 2017-11-01 12:05:49 +09:00
dn_route.c proc: introduce proc_create_seq_private 2018-05-16 07:23:35 +02:00
dn_rules.c net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
dn_table.c net: decnet: dn_table: mark expected switch fall-through 2017-11-11 19:10:06 +09:00
dn_timer.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
Kconfig net/decnet: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:34 -08:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
README
sysctl_net_decnet.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
TODO

                       Linux DECnet Project
                      ======================

The documentation for this kernel subsystem is available in the
Documentation/networking subdirectory of this distribution and also
on line at http://www.chygwyn.com/DECnet/

Steve Whitehouse <SteveW@ACM.org>