linux-sg2042/net/nfc
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
..
hci NFC: Convert timers to use timer_setup() 2017-11-06 01:12:10 +01:00
nci net: annotate ->poll() instances 2017-11-27 16:20:04 -05:00
Kconfig NFC Digital: Add NFC-F technology support 2013-09-25 02:02:25 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
af_nfc.c net: socket: mark socket protocol handler structs as const 2017-05-16 11:54:07 -04:00
core.c NFC: Convert timers to use timer_setup() 2017-11-06 01:12:10 +01:00
digital.h NFC: digital: Add 'tg_listen_md' and 'tg_get_rf_tech' driver hooks 2014-07-23 01:17:31 +02:00
digital_core.c NFC: digital: Abort cmd when deactivating target 2017-11-10 00:03:39 +01:00
digital_dep.c NFC: digital: NFC-DEP Target WT(nfcdep,max) is now 14 2017-06-23 00:19:59 +02:00
digital_technology.c NFC: digital: NFC-A SEL_RES must be one byte 2017-06-23 00:19:59 +02:00
llcp.h net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
llcp_commands.c NFC: llcp: Limit size of SDP URI 2018-02-16 15:16:05 -05:00
llcp_core.c NFC: Convert timers to use timer_setup() 2017-11-06 01:12:10 +01:00
llcp_sock.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
netlink.c net: remove unnecessary genlmsg_cancel() calls 2018-05-29 09:53:38 -04:00
nfc.h nfc: netlink: HCI event connectivity implementation 2015-12-29 19:06:20 +01:00
rawsock.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00