CVS commit: [simonb-wapbl] src/sys/kern

[Greg Oster <oster%netbsd.org@localhost>]

Module Name:    src
Committed By:   oster
Date:           Mon Jul 28 04:04:32 UTC 2008

Modified Files:
        src/sys/kern [simonb-wapbl]: vfs_wapbl.c

Log Message:
Turn on WAPBL_DEBUG_SERIALIZE in order to use RW_WRITER locks instead
of RW_READER locks in wapbl_begin().  Include the following comment as
well:

        XXX: The original code calls for the use of a RW_READER lock
        here, but it turns out there are performance issues with high
        metadata-rate workloads (e.g. multiple simultaneous tar
        extractions).  For now, we force the lock to be RW_WRITER,
        since that currently has the best performance characteristics
        (even for a single tar-file extraction).

Approved by: simonb


To generate a diff of this commit:
cvs rdiff -r1.1.2.10 -r1.1.2.11 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.