system revision 1.7
1 $NetBSD: system,v 1.7 2009/09/21 19:41:23 agc Exp $ 2 3 NetBSD System Roadmap 4 ===================== 5 6 This is a small roadmap document, and deals with the main system 7 aspects of the operating system. 8 9 The following projects are expected to be included in NetBSD 6.0 10 11 1. 64-bit time values supported 12 2. Better Kernel Modules support 13 3. Full kernel preemption for real-time threads 14 4. POSIX shared memory 15 5. namei() tactical changes 16 6. Better resource controls 17 7. Improved observability: online crashdumps, remote debugging 18 8. Processor and cache topology aware scheduler 19 9. namei() strategic changes 20 21 We currently expect to branch 6.0 in the March 2010 timeframe, with a view 22 to a 6.0 release later in 2010. 23 24 We'll continue to update this roadmap as features and dates get firmed up. 25 26 27 Some explanations 28 ================= 29 30 1. 64-bit time_t support 31 ------------------------- 32 33 The Unix 32-bit time_t value will overflow in 2037 - any mortgage calculations 34 which use a time_t value are in danger of overflowing at the present time - 35 and to address this, 64-bit time_t values will be used to contain the number 36 of seconds since 1970. This was completed in 5.99.7 by Christos (with no libc 37 major bump - kudos and respect), and will be in 6.0. 38 39 Responsible: christos 40 41 2. Better Kernel Module Support 42 ------------------------------- 43 44 Starting with 5.99.2, the kernel support for modules was enhanced by 45 ad, and GENERIC was switched over to be a MODULAR kernel. Support 46 from booting from modules, like ffs, was introduced at the same time. 47 Some work has been done by Luke Mewburn in this area to define module 48 locations and paths so that effective kernel development can be done 49 using modules. 50 51 Responsible: ad, lukem 52 53 3. Full kernel preemption for real-time threads on non-x86 54 ---------------------------------------------------------- 55 56 With the revamp of the kernel concurrency model, much of the kernel is 57 fully multi-threaded and can therefore be preempted at any time. In 58 support of lower context switch and dispatch times for real-time 59 threads, full kernel preemption is being implemented. This has been 60 implemented already for i386 and x86_64 (and is in 5.0), but needs to 61 be extended to support the ARM, MIPS and SuperH ports. 62 63 Responsible: rmind 64 65 4. POSIX shared memory 66 ---------------------- 67 68 Implement POSIX shared memory facilities, which can be used to create the 69 shared memory objects and add the memory locations to the address space of 70 a process. 71 72 Responsible: rmind 73 74 5. Incremental namei improvements, Phase 1 75 ------------------------------------------ 76 77 In NetBSD 5.99.15, some changes were made to split the namei() routine 78 up into logical parts, so that changes can be made to the constituent 79 parts in a less intrusive way. This is in the repository now, and will 80 be in 6.0. 81 82 Responsible: dholland 83 84 6. Better resource controls 85 --------------------------- 86 87 A resource provisioning and control framework that extends beyond the 88 traditional Unix process limits. 89 90 7. Improved observability: online crashdumps, remote debugging 91 -------------------------------------------------------------- 92 93 XXX crashdumps while the system is running 94 XXX firewire support in libkvm 95 96 8. Processor and cache topology aware scheduler 97 ----------------------------------------------- 98 99 Implement the detection of the topology of the processors and caches. 100 Improve the scheduler to make decisions about thread migration 101 according to the topology, to get better thread affinity and less 102 cache thrashing, and thus improve overall performance in modern SMP 103 systems. 104 105 Responsible: rmind 106 107 9. Incremental namei improvements, Phase 2 108 ------------------------------------------ 109 110 Building on the namei() split which was introduced in 5.99.15 (see (5) 111 above), further changes will be introduced: see the changes to namei 112 outlined in Message-ID: <20080319053709.GB3951 (a] netbsd.org> for more 113 information. This will simplify the locking and behavior of namei() 114 calls within the kernel to resolve path names within file systems. 115 116 Responsible: dholland 117 118 119 120 Alistair Crooks 121 Mon 21 Sep 2009 08:39:16 BST 122
Indexes created Wed Sep 24 15:09:51 GMT 2025