mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity
1,127,495 Commits 103 Branches 5,011 Tags 5.4 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
Go to file
Damien Le Moal 9148c0b0cf block: mq-deadline: Do not break sequential write streams to zoned HDDs 
commit 015d02f485 upstream.

mq-deadline ensures an in order dispatching of write requests to zoned
block devices using a per zone lock (a bit). This implies that for any
purely sequential write workload, the drive is exercised most of the
time at a maximum queue depth of one.

However, when such sequential write workload crosses a zone boundary
(when sequentially writing multiple contiguous zones), zone write
locking may prevent the last write to one zone to be issued (as the
previous write is still being executed) but allow the first write to the
following zone to be issued (as that zone is not yet being writen and
not locked). This result in an out of order delivery of the sequential
write commands to the device every time a zone boundary is crossed.

While such behavior does not break the sequential write constraint of
zoned block devices (and does not generate any write error), some zoned
hard-disks react badly to seeing these out of order writes, resulting in
lower write throughput.

This problem can be addressed by always dispatching the first request
of a stream of sequential write requests, regardless of the zones
targeted by these sequential writes. To do so, the function
deadline_skip_seq_writes() is introduced and used in
deadline_next_request() to select the next write command to issue if the
target device is an HDD (blk_queue_nonrot() being false).
deadline_fifo_request() is modified using the new
deadline_earlier_request() and deadline_is_seq_write() helpers to ignore
requests in the fifo list that have a preceding request in lba order
that is sequential.

With this fix, a sequential write workload executed with the following
fio command:

fio  --name=seq-write --filename=/dev/sda --zonemode=zbd --direct=1 \
     --size=68719476736  --ioengine=libaio --iodepth=32 --rw=write \
     --bs=65536

results in an increase from 225 MB/s to 250 MB/s of the write throughput
of an SMR HDD (11% increase).

Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20221124021208.242541-3-damien.lemoal@opensource.wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 		2023-01-07 11:15:54 +01:00
Documentation kprobes: kretprobe events missing on 2-core KVM guest 2023-01-04 11:26:27 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch ARM: 9256/1: NWFPE: avoid compiler-generated __aeabi_uldivmod 2023-01-07 11:15:53 +01:00
block block: mq-deadline: Do not break sequential write streams to zoned HDDs 2023-01-07 11:15:54 +01:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: tcrypt - Fix multibuffer skcipher speed test mem leak 2022-12-31 13:26:20 +01:00
drivers drm/amdgpu: fix mmhub register base coding error 2023-01-07 11:15:54 +01:00
fs cifs: set correct status of tcon ipc when reconnecting 2023-01-07 11:15:54 +01:00
include mptcp: remove MPTCP 'ifdef' in TCP SYN cookies 2023-01-07 11:15:48 +01:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2022-12-02 17:43:11 +01:00
io_uring io_uring: dont remove file from msg_ring reqs 2023-01-04 11:26:29 +01:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:25:48 +01:00
kernel tracing: Fix infinite loop in tracing_read_pipe on overflowed print_trace_line 2023-01-07 11:15:52 +01:00
lib test_firmware: fix memory leak in test_firmware_init() 2022-12-31 13:26:26 +01:00
mm mm, compaction: fix fast_isolate_around() to stay within boundaries 2023-01-04 11:26:30 +01:00
net mptcp: use proper req destructor for IPv6 2023-01-07 11:15:48 +01:00
samples samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe() 2022-12-31 13:26:28 +01:00
scripts scripts/faddr2line: Fix regression in name resolution on ppc64le 2022-12-08 11:30:14 +01:00
security ima: Fix hash dependency to correct algorithm 2023-01-07 11:15:50 +01:00
sound ALSA: hda/realtek: Apply dual codec fixup for Dell Latitude laptops 2023-01-07 11:15:47 +01:00
tools selftests: Use optional USERCFLAGS and USERLDFLAGS 2023-01-07 11:15:46 +01:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Update gfn_to_pfn_cache khva when it moves within the same page 2022-12-02 17:43:13 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-14 11:40:58 +01:00
.cocciconfig
…
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Qualcomm ARM64 DTS fixes for 6.0 2022-09-23 16:44:37 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS One MAINTAINERS update, two MM fixes, both cc:stable 2022-10-01 09:13:29 -07:00
Makefile Linux 6.0.17 2023-01-04 11:26:32 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.