linux_dsm_epyc7002/include
Constantine Shulyupin 5da784cce4 fuse: add max_pages to init_out
Replace FUSE_MAX_PAGES_PER_REQ with the configurable parameter max_pages to
improve performance.

Old RFC with detailed description of the problem and many fixes by Mitsuo
Hayasaka (mitsuo.hayasaka.hu@hitachi.com):
 - https://lkml.org/lkml/2012/7/5/136

We've encountered performance degradation and fixed it on a big and complex
virtual environment.

Environment to reproduce degradation and improvement:

1. Add lag to user mode FUSE
Add nanosleep(&(struct timespec){ 0, 1000 }, NULL); to xmp_write_buf in
passthrough_fh.c

2. patch UM fuse with configurable max_pages parameter. The patch will be
provided latter.

3. run test script and perform test on tmpfs
fuse_test()
{

       cd /tmp
       mkdir -p fusemnt
       passthrough_fh -o max_pages=$1 /tmp/fusemnt
       grep fuse /proc/self/mounts
       dd conv=fdatasync oflag=dsync if=/dev/zero of=fusemnt/tmp/tmp \
		count=1K bs=1M 2>&1 | grep -v records
       rm fusemnt/tmp/tmp
       killall passthrough_fh
}

Test results:

passthrough_fh /tmp/fusemnt fuse.passthrough_fh \
	rw,nosuid,nodev,relatime,user_id=0,group_id=0 0 0
1073741824 bytes (1.1 GB) copied, 1.73867 s, 618 MB/s

passthrough_fh /tmp/fusemnt fuse.passthrough_fh \
	rw,nosuid,nodev,relatime,user_id=0,group_id=0,max_pages=256 0 0
1073741824 bytes (1.1 GB) copied, 1.15643 s, 928 MB/s

Obviously with bigger lag the difference between 'before' and 'after'
will be more significant.

Mitsuo Hayasaka, in 2012 (https://lkml.org/lkml/2012/7/5/136),
observed improvement from 400-550 to 520-740.

Signed-off-by: Constantine Shulyupin <const@MakeLinux.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:06 +02:00
..
acpi ACPICA: Update version to 20180810 2018-08-14 23:49:13 +02:00
asm-generic asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO 2018-09-14 09:49:21 +01:00
clocksource
crypto crypto: scatterwalk - remove scatterwalk_samebuf() 2018-08-03 18:06:04 +08:00
drm drm: fix drm_drv_uses_atomic_modeset on non modesetting drivers. 2018-09-18 11:17:06 +02:00
dt-bindings ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
keys
kvm KVM: arm/arm64: vgic-v3: Add core support for Group0 SGIs 2018-08-12 12:06:34 +01:00
linux - Fix Dialog DA9063 regulator constraints issue causing failure in probe 2018-09-23 17:19:27 +02:00
math-emu
media - New Drivers 2018-08-20 15:38:44 -07:00
memory
misc
net tls: zero the crypto information from tls_context before freeing 2018-09-13 12:03:47 -07:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
ras
rdma Second merge window update 2018-08-23 15:34:48 -07:00
scsi SCSI misc on 20180815 2018-08-15 22:06:26 -07:00
soc
sound ASoC: Fixes for v4.19 2018-09-17 18:59:21 +02:00
target scsi: target: add session removal function 2018-08-02 15:29:31 -04:00
trace Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2018-08-24 13:19:27 -07:00
uapi fuse: add max_pages to init_out 2018-10-01 10:07:06 +02:00
video fbdev changes for v4.19: 2018-08-23 15:44:58 -07:00
xen xen/balloon: add runtime control for scrubbing ballooned out pages 2018-09-14 08:51:10 -04:00