Date: Tue, 5 Mar 2002 18:42:57 -0800 (PST) From: Matt Dillon <dillon@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/vm vm_object.c Message-ID: <200203060242.g262gv628201@freefall.freebsd.org>
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dillon 2002/03/05 18:42:57 PST
Modified files:
sys/vm vm_object.c
Log:
Add a sequential iteration optimization to vm_object_page_clean(). This
moderately improves msync's and VM object flushing for objects containing
randomly dirtied pages (fsync(), msync(), filesystem update daemon),
and improves cpu use for small-ranged sequential msync()s in the face of
very large mmap()ings from O(N) to O(1) as might be performed by a database.
A sysctl, vm.msync_flush_flag, has been added and defaults to 3 (the two
committed optimizations are turned on by default). 0 will turn off both
optimizations.
This code has already been tested under stable and is one in a series of
memq / vp->v_dirtyblkhd / fsync optimizations to remove O(N^2) restart
conditions that will be coming down the pipe.
MFC after: 3 days
Revision Changes Path
1.201 +195 -76 src/sys/vm/vm_object.c
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