linux/Documentation
NeilBrown 84dacdbd53 mm: document and polish read-ahead code
Add some "big-picture" documentation for read-ahead and polish the code
to make it fit this documentation.

The meaning of ->async_size is clarified to match its name.  i.e.  Any
request to ->readahead() has a sync part and an async part.  The caller
will wait for the sync pages to complete, but will not wait for the
async pages.  The first async page is still marked PG_readahead

Note that the current function names page_cache_sync_ra() and
page_cache_async_ra() are misleading.  All ra request are partly sync
and partly async, so either part can be empty.  A page_cache_sync_ra()
request will usually set ->async_size non-zero, implying it is not all
synchronous.

When a non-zero req_count is passed to page_cache_async_ra(), the
implication is that some prefix of the request is synchronous, though
the calculation made there is incorrect - I haven't tried to fix it.

Link: https://lkml.kernel.org/r/164549983734.9187.11586890887006601405.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:00 -07:00
..
ABI Power Supply Fixes for 5.17 cycle 2022-02-20 11:07:46 -08:00
accounting - A bunch of fixes: forced idle time accounting, utilization values 2022-01-23 17:35:27 +02:00
admin-guide - Mitigate Spectre v2-type Branch History Buffer attacks on machines 2022-03-07 17:29:47 -08:00
arc docs: ARC: Improve readability 2021-12-10 14:28:01 -07:00
arm Documentation: arm: marvell: Extend Avanta list 2022-01-27 11:22:34 -07:00
arm64 KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata 2022-02-03 09:22:30 +00:00
block docs: block: remove queue-sysfs.rst 2022-01-09 18:59:10 -07:00
bpf bpf, docs: Fully document the JMP mode modifiers 2022-01-05 13:11:26 -08:00
cdrom
core-api mm: document and polish read-ahead code 2022-03-22 15:57:00 -07:00
cpu-freq cpufreq: Reintroduce ready() callback 2022-02-09 13:18:49 +05:30
crypto
dev-tools linux-kselftest-kunit-fixes-5.17-rc4 2022-02-10 15:39:59 -08:00
devicetree ARM: SoC fixes for 5.17, part 3 2022-03-10 11:43:01 -08:00
doc-guide docs: discourage use of list tables 2022-01-07 09:33:13 -07:00
driver-api Three small documentation fixes. 2022-01-22 09:02:57 +02:00
fault-injection
fb
features ARM: 9158/1: leave it to core code to manage thread_info::cpu 2021-12-17 11:34:31 +00:00
filesystems mm: document and polish read-ahead code 2022-03-22 15:57:00 -07:00
firmware_class
firmware-guide Device properties framework updates for 5.17-rc1 2022-01-10 20:48:19 -08:00
fpga
gpu Revert "fbcon: Disable accelerated scrolling" 2022-02-02 15:15:11 +01:00
hid
hwmon hwmon/pmbus: (ir38064) Add support for IR38060, IR38164 IR38263 2021-12-26 15:02:07 -08:00
i2c Docs: Fixes link to I2C specification 2021-12-31 14:39:28 +01:00
ia64
ide
iio
infiniband
input
isdn
kbuild doc: kbuild: fix default in imply table 2022-01-08 18:28:21 +09:00
kernel-hacking docs: fix typo in Documentation/kernel-hacking/locking.rst 2022-01-27 11:22:33 -07:00
leds
litmus-tests
livepatch Documentation: livepatch: Add livepatch API page 2021-12-23 11:35:53 +01:00
locking Documentation/locking/locktypes: Update migrate_disable() bits. 2021-11-30 15:40:31 +01:00
m68k
maintainer
mhi
mips
misc-devices
netlabel
networking This isn't a hugely busy cycle for documentation, but a few significant 2022-01-11 10:00:04 -08:00
nios2
nvdimm
openrisc
parisc
PCI
pcmcia
power Merge branches 'pm-opp', 'pm-devfreq' and 'powercap' 2022-01-10 18:00:31 +01:00
powerpc
process Kbuild updates for v5.17 2022-01-19 11:15:19 +02:00
RCU Merge branches 'doc.2021.11.30c', 'exp.2021.12.07a', 'fastnohz.2021.11.30c', 'fixes.2021.11.30c', 'nocb.2021.12.09a', 'nolibc.2021.11.30c', 'tasks.2021.12.09a', 'torture.2021.12.07a' and 'torturescript.2021.11.30c' into HEAD 2021-12-09 11:38:09 -08:00
riscv riscv: Move KASAN mapping next to the kernel mapping 2022-01-19 17:54:04 -08:00
s390
scheduler docs/scheduler: fix typo and warning in sched-bwc 2021-12-06 12:15:49 -07:00
scsi
security docs: update self-protection __ro_after_init status 2021-12-10 14:02:06 -07:00
sh
sound ALSA: hda/realtek: Add new alc285-hp-amp-init model 2021-12-14 10:44:26 +01:00
sparc
sphinx docs: automarkup.py: Fix invalid HTML link output and broken URI fragments 2022-01-07 09:32:58 -07:00
sphinx-static docs: add support for RTD dark mode 2021-12-10 14:05:55 -07:00
spi spi: pxa2xx: Get rid of unused enable_loopback member 2021-11-29 12:20:00 +00:00
staging Three small documentation fixes. 2022-01-22 09:02:57 +02:00
target
timers rcu: Remove the RCU_FAST_NO_HZ Kconfig option 2021-11-30 17:24:47 -08:00
tools Tracing fixes for 5.17: 2022-02-26 12:10:17 -08:00
trace Three small documentation fixes. 2022-01-22 09:02:57 +02:00
translations cpufreq: Reintroduce ready() callback 2022-02-09 13:18:49 +05:30
tty Documentation: add TTY chapter 2021-11-26 16:27:43 +01:00
usb docs: ABI: fixed req_number desc in UAC1 2021-12-30 12:10:44 +01:00
userspace-api xen: update missing ioctl magic numers documentation 2022-02-03 08:24:34 +01:00
virt Merge branch 'kvm-ppc-cap-210' into kvm-master 2022-02-22 09:07:16 -05:00
vm docs/vm: Fix typo in *harden* 2022-01-27 11:22:34 -07:00
w1
watchdog
x86 x86/sgx: Fix minor documentation issues 2021-11-17 06:36:09 -08:00
xtensa
.gitignore
arch.rst docs: Add documentation for ARC processors 2021-11-29 14:53:11 -07:00
asm-annotations.rst
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py docs: add support for RTD dark mode 2021-12-10 14:05:55 -07:00
COPYING-logo
docutils.conf
dontdiff
index.rst docs: Hook the RTLA documents into the kernel docs build 2022-01-27 11:20:39 -07:00
Kconfig
logo.gif
Makefile docs: address some text issues with css/theme support 2021-12-16 15:54:12 -07:00
memory-barriers.txt asm-generic: introduce io_stop_wc() and add implementation for ARM64 2021-12-22 10:44:53 +00:00
SubmittingPatches
watch_queue.rst