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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-19 18:53:52 +08:00
linux-next/drivers/char
Linus Torvalds 6a965666b7 Pipework for general notification queue
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Merge tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull pipe rework from David Howells:
 "This is my set of preparatory patches for building a general
  notification queue on top of pipes. It makes a number of significant
  changes:

   - It removes the nr_exclusive argument from __wake_up_sync_key() as
     this is always 1. This prepares for the next step:

   - Adds wake_up_interruptible_sync_poll_locked() so that poll can be
     woken up from a function that's holding the poll waitqueue
     spinlock.

   - Change the pipe buffer ring to be managed in terms of unbounded
     head and tail indices rather than bounded index and length. This
     means that reading the pipe only needs to modify one index, not
     two.

   - A selection of helper functions are provided to query the state of
     the pipe buffer, plus a couple to apply updates to the pipe
     indices.

   - The pipe ring is allowed to have kernel-reserved slots. This allows
     many notification messages to be spliced in by the kernel without
     allowing userspace to pin too many pages if it writes to the same
     pipe.

   - Advance the head and tail indices inside the pipe waitqueue lock
     and use wake_up_interruptible_sync_poll_locked() to poke poll
     without having to take the lock twice.

   - Rearrange pipe_write() to preallocate the buffer it is going to
     write into and then drop the spinlock. This allows kernel
     notifications to then be added the ring whilst it is filling the
     buffer it allocated. The read side is stalled because the pipe
     mutex is still held.

   - Don't wake up readers on a pipe if there was already data in it
     when we added more.

   - Don't wake up writers on a pipe if the ring wasn't full before we
     removed a buffer"

* tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  pipe: Remove sync on wake_ups
  pipe: Increase the writer-wakeup threshold to reduce context-switch count
  pipe: Check for ring full inside of the spinlock in pipe_write()
  pipe: Remove redundant wakeup from pipe_write()
  pipe: Rearrange sequence in pipe_write() to preallocate slot
  pipe: Conditionalise wakeup in pipe_read()
  pipe: Advance tail pointer inside of wait spinlock in pipe_read()
  pipe: Allow pipes to have kernel-reserved slots
  pipe: Use head and tail pointers for the ring, not cursor and length
  Add wake_up_interruptible_sync_poll_locked()
  Remove the nr_exclusive argument from __wake_up_sync_key()
  pipe: Reduce #inclusion of pipe_fs_i.h
2019-11-30 14:12:13 -08:00
..
agp char: Fix Kconfig indentation 2019-11-20 15:09:48 +01:00
hw_random Char/Misc driver patches for 5.5-rc1 2019-11-27 10:53:50 -08:00
ipmi Char/Misc driver patches for 5.5-rc1 2019-11-27 10:53:50 -08:00
mwave treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
pcmcia treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18 2019-05-21 11:28:46 +02:00
tpm tpm: Switch to platform_get_irq_optional() 2019-11-12 21:45:37 +02:00
xilinx_hwicap treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xillybus char: xillybus: use devm_platform_ioremap_resource() to simplify code 2019-11-05 18:29:21 +01:00
adi.c char: sparc64: Add privileged ADI driver 2018-06-05 11:24:55 -07:00
apm-emulation.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
applicom.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
applicom.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bsr.c Merge 5.2-rc4 into char-misc-next 2019-06-09 09:11:21 +02:00
ds1620.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
dsp56k.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
dtlk.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
efirtc.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
hangcheck-timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 405 2019-06-05 17:37:13 +02:00
hpet.c hpet: Fix division by zero in hpet_time_div() 2019-07-25 14:39:51 +02:00
Kconfig char: Fix Kconfig indentation 2019-11-20 15:09:48 +01:00
lp.c lp: fix sparc64 LPSETTIMEOUT ioctl 2019-11-13 19:08:22 +08:00
Makefile char: remove the SGI tiocx/mbcs driver 2019-08-16 11:33:56 -07:00
mem.c Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
misc.c char: misc: Move EXPORT_SYMBOL immediately next to the functions/varibles 2019-05-24 18:00:41 +02:00
mspec.c char/mspec: remove SGI SN2 support 2019-08-16 11:33:56 -07:00
nsc_gpio.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
nvram.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
nwbutton.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
nwbutton.h treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
nwflash.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
pc8736x_gpio.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
powernv-op-panel.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
ppdev.c ppdev: fix PPGETTIME/PPSETTIME ioctls 2019-11-13 19:08:21 +08:00
ps3flash.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 164 2019-05-30 11:26:38 -07:00
random.c Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-11-16 18:14:32 -08:00
raw.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
rtc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
scx200_gpio.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
sonypi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
tb0219.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
tlclk.c tlclk: clean an indentation issue, remove extraneous tabs 2018-11-11 12:58:27 -08:00
toshiba.c toshiba: Add correct printk log level while emitting error log 2019-09-04 13:42:43 +02:00
ttyprintk.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 402 2019-06-05 17:37:13 +02:00
uv_mmtimer.c
virtio_console.c Pipework for general notification queue 2019-11-30 14:12:13 -08:00