Hello, this is a mini-HEADSUP mainly targeted at those working on the
kernel source in FreeBSD-CURRENT.
In short, for the mbuf subsystem:
M_WAIT is now deprecated and M_TRYWAIT should be used in its place.
Summary:
This ONLY applies to allocations for the "mbuf subsystem" and NOT any
allocations with malloc() or any other subsystems:
The M_WAIT flag has been renamed to M_TRYWAIT. The commit message
explains the reason for the rename. It basically has to do with the
developer needing to check whether calls to m_get(), m_gethdr() (and
their macro equivalents MGET and MGETHDR) as well as calls to the mbuf
cluster allocation routines and macros return a NULL pointer. In other
words, even calls with M_(TRYWAIT) may fail in allocating mbufs or mbuf
clusters and therefore must be accompanied by a check for that failure.
This has been the case for a while and the time spent blocking/waiting
for resources is tunable with the kern.ipc.mbuf_wait sysctl. The flag
name has been changed in an effort to "communicate the right message" to
developers, especially those porting code from NetBSD and OpenBSD where
M_WAIT means "block indefinetely if you can't get me anything."
M_WAIT is now deprecated and M_TRYWAIT should be used in its place.
Happy Holidays!
Bosko Milekic
[EMAIL PROTECTED]
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message
