Konstantin Belousov c480f781ea Current implementations of sync(2) and syncer vnode fsync() VOP uses ... mnt_noasync counter to temporary remove MNTK_ASYNC mount option, which is needed to guarantee a synchronous completion of the initiated i/o before syscall or VOP return. Global removal of MNTK_ASYNC option is harmful because not only i/o started from corresponding thread becomes synchronous, but all i/o is synchronous on the filesystem which is initiated during sync(2) or syncer activity. Instead of removing MNTK_ASYNC from mnt_kern_flag, provide a local thread flag to disable async i/o for current thread only. Use the opportunity to move DOINGASYNC() macro into sys/vnode.h and consistently use it through places which tested for MNTK_ASYNC. Some testing demonstrated 60-70% improvements in run time for the metadata-intensive operations on async-mounted UFS volumes, but still with great deviation due to other reasons. Reviewed by: mckusick Tested by: scottl MFC after: 2 weeks		2012-02-06 11:04:36 +00:00
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g_journal_ufs.c
g_journal.c	Current implementations of sync(2) and syncer vnode fsync() VOP uses	2012-02-06 11:04:36 +00:00
g_journal.h	Make it possible to use gjournal for the root filesystem. Previously,	2008-12-06 11:33:10 +00:00