Note: this is my personal todo and ideas list (alexh@)
Add a simple (regression) test framework
- Add the hundreds of test cases from our bugtracker
- Run nightly/weekly or at least before a release
- add a callout_init_mtx/lock, etc
- add callout_drain
Improve installer crypto support
- add tcplay/TrueCrypt support
- let user choose crypto algorithm, IV generation, etc
Add support for hyperthreading / other SMT to our scheduler
- distinguish between real cores and threads on the same core
- Linux' work in the area: http://lwn.net/Articles/8553/
Take advantage of nested paging/EPT in vkernels
add a non-persistent unionfs VFS
- while this does not fully replace unionfs, it would deal with a few of the situations where unionfs is useful
- additionally the complexity is much lower, since everything can be kept in memory
bring the samba3 hammer shadow copy foo to maturity
extend dm's message feature to be two-way? what's the benefit?
make the whole system deal correctly with non-512-byte blocksize for disks. (DEV_BSIZE)
add another optimized bcopy/memcpy/memset/bzero version, using the AVX instructions
cryptdisks: multiple keyfile support
Add geli (without integrity verification) support using dm_target_crypt?
- a bit like the recent TrueCrypt implementation (tcplay)
Keep opencrypto up-to-date
Port hwpmc & dig into (boot-up) performance
- port to x86_64
- separate out common arch parts (linprocfs, for example)
Fix the crash analysis script (or rather the programs it calls [some segfault])
Take a look at updating lvm/dm/libdevicemapper
Take a look at importing dmctl from NetBSD
- would require a bunch of modifications to work with the proper device-mapper API
- also some extensions? missing lots of features
rip out the disk partitioning from the disk subsystem and implement it in a more general fashion
- crazy idea: as dm targets with an auto-configuration option!
- would require to be able to create dm targets with an arbitrary name and not in /dev/mapper
ATA (automatic) spindown (see FreeBSD current)
Update callout http://svn.freebsd.org/viewvc/base?view=revision&revision=127969
inv ctxsw rusage
- see irc logs
- some incorrect accounting going on, don't remember details
- make it work without whiteout
Fix ipsec, get rid of old ipsec
sync up vr
- Added VT6105M specific register definitions. VT6105M has the following hardware capabilities.
- Tx/Rx IP/TCP/UDP checksum offload.
- VLAN hardware tag insertion/extraction. Due to lack of information for getting extracted VLAN tag in Rx path, VLAN hardware support was not implemented yet.
- CAM(Content Addressable Memory) based 32 entry perfect multicast/ VLAN filtering.
- 8 priority queues. o Implemented CAM based 32 entry perfect multicast filtering for VT6105M. If number of multicast entry is greater than 32, vr(4) uses traditional hash based filtering.
RedZone, a buffer corruption protection for the kernel malloc(9) facility has been implemented.
- This detects both buffer underflows and overflows at runtime on free(9) and realloc(9), and prints backtraces from where memory was allocated and from where it was freed.
- see irc log below.
port uart driver
port wscons or update syscons
- probably way too much effort (wscons)
- wrapper is included for userland; should be easy to port
suspend/resume for SMP x86
[alexh@leaf:~/home] $ roundup-server -p 8080 bt=bugtracker
-05:48- : dillon@: no, double frees to the object cache are nasty. It can't detect them. the object winds up in the magazine array twice -05:48- : dillon@: (and possibly different magazines, too) -05:49- : alexh@: can't I just write some magic to a free object on the first objcache_put and check if it's there on objcache_put? -05:49- : alexh@: and clear it on objcache_get, anyways -05:50- : dillon@: no, because the object is still may have live-initialized fields -05:50- : dillon@: because it hasn't been dtor'ed yet (one of the features of the objcache, to avoid having to reinitialize objects every time) -05:50- : dillon@: the mbuf code uses that feature I think, probably other bits too -05:51- : dillon@: theoretically we could allocate slightly larger objects and store a magic number at offset [-1] or something like that, but it gets a little iffy doing that -05:52- : dillon@: the objcache with the objcache malloc default could probably do something like that I guess. -05:52- : dillon@: I don't consider memory tracking to be a huge issue w/ dragonfly, though I like the idea of being able to do it. It is a much bigger problem in FreeBSD due to the large number of committers -05:55- : dillon@: For the slab allocator you may be able to do something using the Zone header. -05:55- : dillon@: the slab allocator in fact I think already has optional code to allocate a tracking bitmap to detect double-frees -05:56- : dillon@: sorry, I just remembered the bit about the power-of-2 allocations -05:56- : dillon@: for example, power-of-2-sized allocations are guaranteed not only to be aligned on that particular size boundary, but also to not cross a PAGE_BOUNDARY (unless the size is > PAGE_SIZE) -05:57- : dillon@: various subsystems such as AHCI depend on that behavior to allocate system structures for which the chipsets only allow one DMA descriptor. -05:59- : alexh@: http://svn.freebsd.org/viewvc/base/head/sys/vm/redzone.c?view=markup&pathrev=155086 < this is redzone. it basically calls redzone_addr_ntor() to increase the size in malloc(), and then redzone_setup() just before returning the chunk -06:02- : dillon@: jeeze. that looks horrible. -06:03- : alexh@: I don't quite get that nsize + redzone_roundup(nsize) -06:03- : dillon@: I don't get it either. It would completely break power-of-2-sized alignments in the original request -06:04- : dillon@: hmmm. well, no it won't break them, but the results are oging to be weird -06:04- : dillon@: ick. -06:15- : dillon@: if the original request is a power of 2 the redzone adjusted request must be a power of 2 -06:15- : dillon@: basically -06:16- : dillon@: so original request 64, redzone request must be 128, 256, 512, 1024, etc. -06:16- : alexh@: yah, k -06:16- : dillon@: original request 32, current redzone code would be 32+128 which is WRONG. -06:16- : alexh@: how big is PAGE_SIZE ? -06:16- : dillon@: 4096 on i386 and amd64 -06:17- : alexh@: and one single malloc can't be bigger than that? -06:17- : dillon@: I'm fairly sure our kmalloc does not guarantee alignment past PAGE_SIZE (that is, the alignment will be only PAGE_SIZE eve if you allocate PAGE_SIZE*2) -06:17- : dillon@: a single kmalloc can be larger then PAGE_SIZe -06:18- : dillon@: it will use the zone up to around 1/2 the zone size (~64KB I think), after which it allocates pages directly with the kernel kvm allocator -06:18- : dillon@: if you look at the kmalloc code you will see the check for oversized allocations -06:18- : alexh@: yah, saw that -06:18- : alexh@: "handle large allocations directly" -06:19- : alexh@: not sure how to do this, really, as the size is obviously also changed in kmem_slab_alloc -06:20- : alexh@: but kmem_slab_alloc isn't called always, is it? -06:20- : alexh@: only if the req doesn't fit into an existant zone -06:20- : dillon@: right -06:20- : dillon@: you don't want to redzone the zone allocation itself