system revision 1.10
1 1.10 agc $NetBSD: system,v 1.10 2012/01/15 03:11:13 agc Exp $ 2 1.1 agc 3 1.1 agc NetBSD System Roadmap 4 1.2 jmmv ===================== 5 1.1 agc 6 1.1 agc This is a small roadmap document, and deals with the main system 7 1.1 agc aspects of the operating system. 8 1.1 agc 9 1.9 agc The following projects will appear in NetBSD 6.0: 10 1.6 agc 1. 64-bit time values supported 11 1.6 agc 2. Better Kernel Modules support 12 1.8 agc 5. namei() tactical changes 13 1.9 agc 9. namei() strategic changes 14 1.8 agc 10. emap (ephemeral mapping) support for i386 and amd64 15 1.8 agc 11. support for mDNSResponder 16 1.8 agc 17 1.9 agc The following projects may make it into future releases: 18 1.6 agc 3. Full kernel preemption for real-time threads 19 1.6 agc 4. POSIX shared memory 20 1.6 agc 6. Better resource controls 21 1.6 agc 7. Improved observability: online crashdumps, remote debugging 22 1.6 agc 8. Processor and cache topology aware scheduler 23 1.1 agc 24 1.1 agc We'll continue to update this roadmap as features and dates get firmed up. 25 1.1 agc 26 1.1 agc 27 1.1 agc Some explanations 28 1.1 agc ================= 29 1.1 agc 30 1.6 agc 1. 64-bit time_t support 31 1.1 agc ------------------------- 32 1.1 agc 33 1.1 agc The Unix 32-bit time_t value will overflow in 2037 - any mortgage calculations 34 1.1 agc which use a time_t value are in danger of overflowing at the present time - 35 1.1 agc and to address this, 64-bit time_t values will be used to contain the number 36 1.7 agc of seconds since 1970. This was completed in 5.99.7 by Christos (with no libc 37 1.7 agc major bump - kudos and respect), and will be in 6.0. 38 1.1 agc 39 1.1 agc Responsible: christos 40 1.1 agc 41 1.10 agc 42 1.6 agc 2. Better Kernel Module Support 43 1.6 agc ------------------------------- 44 1.6 agc 45 1.6 agc Starting with 5.99.2, the kernel support for modules was enhanced by 46 1.6 agc ad, and GENERIC was switched over to be a MODULAR kernel. Support 47 1.6 agc from booting from modules, like ffs, was introduced at the same time. 48 1.6 agc Some work has been done by Luke Mewburn in this area to define module 49 1.6 agc locations and paths so that effective kernel development can be done 50 1.8 agc using modules. Kernel modules have been moved out of base.tgz and a new 51 1.8 agc modules.tgz has been created. 52 1.6 agc 53 1.6 agc Responsible: ad, lukem 54 1.6 agc 55 1.10 agc 56 1.7 agc 3. Full kernel preemption for real-time threads on non-x86 57 1.7 agc ---------------------------------------------------------- 58 1.5 agc 59 1.7 agc With the revamp of the kernel concurrency model, much of the kernel is 60 1.7 agc fully multi-threaded and can therefore be preempted at any time. In 61 1.7 agc support of lower context switch and dispatch times for real-time 62 1.7 agc threads, full kernel preemption is being implemented. This has been 63 1.7 agc implemented already for i386 and x86_64 (and is in 5.0), but needs to 64 1.10 agc be extended to support ARM and other ports. MIPS has this, as does 65 1.10 agc PowerPC, but it is not yet enabled. 66 1.7 agc 67 1.7 agc Responsible: rmind 68 1.5 agc 69 1.9 agc 70 1.6 agc 4. POSIX shared memory 71 1.6 agc ---------------------- 72 1.1 agc 73 1.10 agc Implement POSIX shared memory facilities, which can be used to create 74 1.10 agc the shared memory objects and add the memory locations to the address 75 1.10 agc space of a process. Changes were proposed on tech-kern, although 76 1.10 agc there were some concerns with the kernel implementation, and so a 77 1.10 agc different approach using wrapper functions on tmpfs is being aimed at 78 1.10 agc for 6.0. 79 1.1 agc 80 1.1 agc Responsible: rmind 81 1.1 agc 82 1.9 agc 83 1.6 agc 5. Incremental namei improvements, Phase 1 84 1.6 agc ------------------------------------------ 85 1.1 agc 86 1.6 agc In NetBSD 5.99.15, some changes were made to split the namei() routine 87 1.6 agc up into logical parts, so that changes can be made to the constituent 88 1.7 agc parts in a less intrusive way. This is in the repository now, and will 89 1.7 agc be in 6.0. 90 1.1 agc 91 1.1 agc Responsible: dholland 92 1.1 agc 93 1.9 agc 94 1.6 agc 6. Better resource controls 95 1.6 agc --------------------------- 96 1.1 agc 97 1.1 agc A resource provisioning and control framework that extends beyond the 98 1.1 agc traditional Unix process limits. 99 1.1 agc 100 1.9 agc Responsible: TBD 101 1.9 agc 102 1.9 agc 103 1.6 agc 7. Improved observability: online crashdumps, remote debugging 104 1.6 agc -------------------------------------------------------------- 105 1.1 agc 106 1.1 agc XXX crashdumps while the system is running 107 1.1 agc XXX firewire support in libkvm 108 1.1 agc 109 1.9 agc Responsible: TBD 110 1.9 agc 111 1.9 agc 112 1.6 agc 8. Processor and cache topology aware scheduler 113 1.6 agc ----------------------------------------------- 114 1.1 agc 115 1.1 agc Implement the detection of the topology of the processors and caches. 116 1.1 agc Improve the scheduler to make decisions about thread migration 117 1.1 agc according to the topology, to get better thread affinity and less 118 1.1 agc cache thrashing, and thus improve overall performance in modern SMP 119 1.10 agc systems. Code has been written, but did not show any performance 120 1.10 agc impreovment. We will continue to monitor this area. 121 1.1 agc 122 1.1 agc Responsible: rmind 123 1.1 agc 124 1.9 agc 125 1.6 agc 9. Incremental namei improvements, Phase 2 126 1.6 agc ------------------------------------------ 127 1.1 agc 128 1.7 agc Building on the namei() split which was introduced in 5.99.15 (see (5) 129 1.7 agc above), further changes will be introduced: see the changes to namei 130 1.7 agc outlined in Message-ID: <20080319053709.GB3951 (a] netbsd.org> for more 131 1.7 agc information. This will simplify the locking and behavior of namei() 132 1.7 agc calls within the kernel to resolve path names within file systems. 133 1.1 agc 134 1.1 agc Responsible: dholland 135 1.1 agc 136 1.1 agc 137 1.8 agc 10. Ephemeral Mapping 138 1.8 agc --------------------- 139 1.8 agc 140 1.8 agc Responsible: rmind 141 1.8 agc 142 1.8 agc 143 1.8 agc 11. Multicast DNS and DNS Service Discovery 144 1.8 agc ------------------------------------------- 145 1.8 agc 146 1.8 agc mDNSResponder (also known as mdnsd on some systems) is a daemon invoked 147 1.8 agc at boot time to implement Multicast DNS and DNS Service Discovery. On Mac 148 1.8 agc OS X 10.6 (Snow Leopard), mDNSResponder is also the system-wide Unicast 149 1.8 agc DNS Resolver. Ty Sarna added support for mdnsd to NetBSD-current, and it 150 1.8 agc will appear in NetBSD 6.0. 151 1.8 agc 152 1.1 agc 153 1.5 agc Alistair Crooks 154 1.9 agc Sat Jan 14 11:40:49 PST 2012 155
Indexes created Fri Sep 26 08:10:20 GMT 2025