Date: Sun, 13 Feb 2005 21:51:50 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/dev/md md.c Message-ID: <200502132151.j1DLpoLO035854@repoman.freebsd.org>
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alc 2005-02-13 21:51:50 UTC
FreeBSD src repository
Modified files:
sys/dev/md md.c
Log:
Request a CPU private mapping from sf_buf_alloc(). If the swap-backed
memory disk is larger than the number of available sf_bufs, this improves
performance on SMPs by eliminating interprocessor TLB shootdowns. For
example, with 6656 sf_bufs, the default on my test machine, and a 256MB
swap-backed memory disk, I see the command
"dd if=/dev/md0 of=/dev/null bs=64k" achieve ~489MB/sec with the default,
shared mappings, and ~587MB/sec with CPU private mappings.
Revision Changes Path
1.153 +6 -1 src/sys/dev/md/md.c
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