CVS commit: src/sys/kern

["Jaromir Dolecek" <jdolecek%netbsd.org@localhost>]

Module Name:    src
Committed By:   jdolecek
Date:           Sat Dec  2 17:29:55 UTC 2017

Modified Files:
        src/sys/kern: vfs_wapbl.c

Log Message:
according to benchmark extracting pkgsrc.tar, using FUA and hence waiting
for each transfer to write through to the medium is way slower than just
letting the drive use a cached write and doing DIOCCACHESYNC on the end

Results were (fs block 32KB / frag 4KB, partition aligned on 32KB boundary):
HDD at siisata(4):  no-FUA: 108 sec w/FUA: 294 sec
SSD at ahcisata(4): no-FUA:  73 sec w/FUA: 502 sec

change the flag so that FUA is only used for the commit block write;
for journal data write, only pass DPO, rely on the cache flush to get them
to media


To generate a diff of this commit:
cvs rdiff -u -r1.100 -r1.101 src/sys/kern/vfs_wapbl.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.