FreeBSD 5.4 Open Issues

Open Issues

This is the beginning of a list of open issues that need to be worked on or resolved for FreeBSD 5.4. If you have any updates for this list, please e-mail re@FreeBSD.org. The feature list for 5.4 is still a work in progress, so items may be added, removed, or modified before we're done.

Show stopper defects for 5.4-RELEASE

Issue	Status	Responsible	Description

Required features for 5.4-RELEASE

Issue	Status	Responsible	Description

Desired features for 5.4-RELEASE

Issue	Status	Responsible	Description
KAME IPSEC without the Giant Lock	In progress	George V. Neville-Neil	Currently, the KAME IPSEC implementation contains inadequate locking to operate without the Giant lock over the network stack, forcing kernels compiled with the KAME IPSEC implementation (not FAST_IPSEC) to run the network stack with the Giant lock, reducing parallelism, increasing lock contention, and increasing latency by preventing preemption. For 5.4-RELEASE, it is desirable to complete the locking work for KAME IPSEC so that it can run without the Giant lock.
All Network Interface Drivers MPSAFE	In progress	--	Currently, some network interface drivers are not safe without the Giant lock due to missing synchronization. These drivers are protected by running non-INTR_MPSAFE and with the IFF_NEEDSGIANT flag set, which cause interrupt threads to acquire the Giant lock before executing the driver's interrupt handler, and to perform if_start (interface transmit start) asynchronously once the Giant lock can be acquired. This results in these drivers performing less well due to increased lock contention, decreased ability to preempt, and latency associated with asynchronous launching of latency-critical events. For 5.4, all network drivers should be able to operate without the Giant lock.
NetIPX without the Giant Lock	In progress	Robert Watson	Currently, the IPX/SPX (netipx) implementation contains inadequate locking to operate without the Giant lock over the network stack, forcing kernels compiled with IPX support to run the network stack with the Giant lock, reducing parallelism, increasing lock contention, and increasing latency by preventing preemption. For 5.4-RELEASE, it is desirable to complete the locking work for IPX so that it can run without the Giant lock.
Fix regression in file(1)	--	--	The new version of file(1) does not cross-build properly. If sparc64 executables are built on i386 the compiled magic numbers file that gets installed is wrong and file(1) doesn't work properly.
SIGABRT under load	In progress	Alan L. Cox	Under very high load (Kris sees this on the package builders) a limitation of 16 sumultaneous exec's may be hit in exec_map(). A workaround has been implemented with a fix planned for 5.5.
DDB_UNATTENDED may not work	Not done	--	There are reports of problems getting dumps after panics.
fix for ttywakeup panic	In progress	Doug White	There appears to be a race condition opening/closing ttys.

Documentation items that must be resolved for 5.4

Issue	Status	Responsible	Description

Testing focuses for 5.4-RELEASE

Issue	Status	Responsible	Description
File descriptor locking	Done	Jeff Roberson	File descriptor locking needs to be merged back from HEAD.
IPFilter mpsafe fixes	Done	Robert Watson	IPFilter is currently not mpsafe but doesn't run with Giant.
Update sysinstall to handle separate packages CD	Done	John Baldwin	Avoid the need for a disc1-gnome/disc1-kde as was done for 4.11
busdma fixes	Done	Scott Long	More work is needed on busdma to fix bounce buffer problems.
AMR driver MPSAFE	Done	Scott Long	Making the AMR driver MPSAFE will greatly increase its performance.
CARP support	Done	Gleb Smirnoff	Common Address Redundancy Protocol allows multiple hosts on the same local network to share a set of IP addresses.
kstack overflows in softupdates	Done	--	There had been reports of kernel stack overflows in softupdates code that caused filesystem problems on reboot. This was fixed during the early stage of code freeze but should be tested.
ATAPI CDROMs in PIO mode during install	Done	Ken Smith	People are having difficulties with various ATAPI CDROMs on various architectures. We need to either do all installs in PIO mode or provide a boot menu method of selecting it.
truss not working	Done	Jeff Roberson	See PR kern/78664.
Deadlock under heavy interrupt load on MP Opteron systems	Done	Doug White	A deadlock related to delivering IPIs on AMD 64-bit processors has been identified.
SCHED_ULE update	Done	Jeff Roberson	Many improvements have been made to the ULE scheduler in 6-CURRENT. These should be merged back to 5.4. The merging is done but ULE is still known to cause panics for some people, especially on SMP systems. Try it with extreme caution.

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