openntpd-openbsd

Source code pulled from OpenBSD for OpenNTPD. The place to contribute to this code is via the OpenBSD CVS tree.

otto 0ec9d0391a Up until now, malloc scanned the bits of the chunk bitmap from position zero, skipping a random number of free slots and then picking the next free one. This slowed things down, especially if the number of full slots increases. This changes the scannning to start at a random position in the bitmap and then taking the first available free slot, wrapping if the end of the bitmap is reached. Of course we'll still scan more if the bitmap becomes more full, but the extra iterations skipping free slots and then some full slots are avoided. The random number is derived from a global, which is incremented by a few random bits every time a chunk is needed (with a small optimization if only one free slot is left). Thanks to the testers!	13 years ago
src	Up until now, malloc scanned the bits of the chunk bitmap from	13 years ago

otto 0ec9d0391a Up until now, malloc scanned the bits of the chunk bitmap from

position zero, skipping a random number of free slots and then
picking the next free one. This slowed things down, especially if
the number of full slots increases.
This changes the scannning to start at a random position in the
bitmap and then taking the first available free slot, wrapping if
the end of the bitmap is reached. Of course we'll still scan more
if the bitmap becomes more full, but the extra iterations skipping
free slots and then some full slots are avoided.
The random number is derived from a global, which is incremented
by a few random bits every time a chunk is needed (with a small optimization
if only one free slot is left).
Thanks to the testers!

13 years ago

src

Up until now, malloc scanned the bits of the chunk bitmap from

13 years ago