system revision 1.8
1 $NetBSD: system,v 1.8 2009/11/17 21:09:54 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 already in NetBSD-current and will appear 10 in NetBSD 6.0: 11 12 1. 64-bit time values supported 13 2. Better Kernel Modules support 14 5. namei() tactical changes 15 10. emap (ephemeral mapping) support for i386 and amd64 16 11. support for mDNSResponder 17 18 The following projects are expected to be included in NetBSD 6.0 19 20 3. Full kernel preemption for real-time threads 21 4. POSIX shared memory 22 6. Better resource controls 23 7. Improved observability: online crashdumps, remote debugging 24 8. Processor and cache topology aware scheduler 25 9. namei() strategic changes 26 27 We currently expect to branch 6.0 in the March 2010 timeframe, with a view 28 to a 6.0 release later in 2010. 29 30 We'll continue to update this roadmap as features and dates get firmed up. 31 32 33 Some explanations 34 ================= 35 36 1. 64-bit time_t support 37 ------------------------- 38 39 The Unix 32-bit time_t value will overflow in 2037 - any mortgage calculations 40 which use a time_t value are in danger of overflowing at the present time - 41 and to address this, 64-bit time_t values will be used to contain the number 42 of seconds since 1970. This was completed in 5.99.7 by Christos (with no libc 43 major bump - kudos and respect), and will be in 6.0. 44 45 Responsible: christos 46 47 2. Better Kernel Module Support 48 ------------------------------- 49 50 Starting with 5.99.2, the kernel support for modules was enhanced by 51 ad, and GENERIC was switched over to be a MODULAR kernel. Support 52 from booting from modules, like ffs, was introduced at the same time. 53 Some work has been done by Luke Mewburn in this area to define module 54 locations and paths so that effective kernel development can be done 55 using modules. Kernel modules have been moved out of base.tgz and a new 56 modules.tgz has been created. 57 58 Responsible: ad, lukem 59 60 3. Full kernel preemption for real-time threads on non-x86 61 ---------------------------------------------------------- 62 63 With the revamp of the kernel concurrency model, much of the kernel is 64 fully multi-threaded and can therefore be preempted at any time. In 65 support of lower context switch and dispatch times for real-time 66 threads, full kernel preemption is being implemented. This has been 67 implemented already for i386 and x86_64 (and is in 5.0), but needs to 68 be extended to support the ARM, MIPS and SuperH ports. 69 70 Responsible: rmind 71 72 4. POSIX shared memory 73 ---------------------- 74 75 Implement POSIX shared memory facilities, which can be used to create the 76 shared memory objects and add the memory locations to the address space of 77 a process. 78 79 Responsible: rmind 80 81 5. Incremental namei improvements, Phase 1 82 ------------------------------------------ 83 84 In NetBSD 5.99.15, some changes were made to split the namei() routine 85 up into logical parts, so that changes can be made to the constituent 86 parts in a less intrusive way. This is in the repository now, and will 87 be in 6.0. 88 89 Responsible: dholland 90 91 6. Better resource controls 92 --------------------------- 93 94 A resource provisioning and control framework that extends beyond the 95 traditional Unix process limits. 96 97 7. Improved observability: online crashdumps, remote debugging 98 -------------------------------------------------------------- 99 100 XXX crashdumps while the system is running 101 XXX firewire support in libkvm 102 103 8. Processor and cache topology aware scheduler 104 ----------------------------------------------- 105 106 Implement the detection of the topology of the processors and caches. 107 Improve the scheduler to make decisions about thread migration 108 according to the topology, to get better thread affinity and less 109 cache thrashing, and thus improve overall performance in modern SMP 110 systems. 111 112 Responsible: rmind 113 114 9. Incremental namei improvements, Phase 2 115 ------------------------------------------ 116 117 Building on the namei() split which was introduced in 5.99.15 (see (5) 118 above), further changes will be introduced: see the changes to namei 119 outlined in Message-ID: <20080319053709.GB3951 (a] netbsd.org> for more 120 information. This will simplify the locking and behavior of namei() 121 calls within the kernel to resolve path names within file systems. 122 123 Responsible: dholland 124 125 126 10. Ephemeral Mapping 127 --------------------- 128 129 Responsible: rmind 130 131 132 11. Multicast DNS and DNS Service Discovery 133 ------------------------------------------- 134 135 mDNSResponder (also known as mdnsd on some systems) is a daemon invoked 136 at boot time to implement Multicast DNS and DNS Service Discovery. On Mac 137 OS X 10.6 (Snow Leopard), mDNSResponder is also the system-wide Unicast 138 DNS Resolver. Ty Sarna added support for mdnsd to NetBSD-current, and it 139 will appear in NetBSD 6.0. 140 141 142 Alistair Crooks 143 Thu Nov 5 07:47:34 PST 2009 144
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