linux-stable/net/llc
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
..
af_llc.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
Kconfig
llc_c_ac.c llc: delete timers synchronously in llc_sk_free() 2018-04-22 14:55:03 -04:00
llc_c_ev.c
llc_c_st.c llc: Make llc_conn_ev_qfyr_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_conn.c llc: delete timers synchronously in llc_sk_free() 2018-04-22 14:55:03 -04:00
llc_core.c net, llc: convert llc_sap.refcnt from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
llc_if.c net: llc: include linux/errno.h instead of asm/errno.h 2014-10-24 15:51:42 -04:00
llc_input.c locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
llc_output.c llc: remove noisy WARN from llc_mac_hdr_init 2014-01-28 18:01:32 -08:00
llc_pdu.c
llc_proc.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
llc_s_ac.c
llc_s_ev.c
llc_s_st.c llc: Make llc_sap_action_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_sap.c net: llc: drop VLA in llc_sap_mcast() 2018-03-12 11:14:06 -04:00
llc_station.c llc2: Collapse remainder of state machine into simple if-else if-statement 2012-09-17 13:04:19 -04:00
Makefile
sysctl_net_llc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00