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authorbde <bde@FreeBSD.org>1996-06-17 12:43:04 +0000
committerbde <bde@FreeBSD.org>1996-06-17 12:43:04 +0000
commit501044728620e5a296b82f0ab2bae44a27b2d661 (patch)
tree3f63b260207bfa855155aa2238d005e661846b33 /sys/kern/subr_diskslice.c
parent0a87e3a7fa8817e4601100fc52862340c63c099e (diff)
downloadFreeBSD-src-501044728620e5a296b82f0ab2bae44a27b2d661.zip
FreeBSD-src-501044728620e5a296b82f0ab2bae44a27b2d661.tar.gz
In microtime(), use pushfl/popfl to preserve the interrupt enable flag
instead of sti to it restore to its usual state. pushfl/popfl is actually faster in protected mode on Pentiums (4+3 cycles instead of 9), and using sti made it extremely inconvenient to call microtime() from fast interrupt handlers. pushfl/popfl is a couple of cycles slower than sti on 486's and a couple more cycles slower on 386's, but the relative cost of using it is not large since microtime() has to use slow i/o instructions on the old cpus.
Diffstat (limited to 'sys/kern/subr_diskslice.c')
0 files changed, 0 insertions, 0 deletions
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