system revision 1.7
1 1.7 agc $NetBSD: system,v 1.7 2009/09/21 19:41:23 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 1.6 agc The following projects are expected to be included in NetBSD 6.0 10 1.1 agc 11 1.6 agc 1. 64-bit time values supported 12 1.6 agc 2. Better Kernel Modules support 13 1.6 agc 3. Full kernel preemption for real-time threads 14 1.6 agc 4. POSIX shared memory 15 1.6 agc 5. namei() tactical changes 16 1.6 agc 6. Better resource controls 17 1.6 agc 7. Improved observability: online crashdumps, remote debugging 18 1.6 agc 8. Processor and cache topology aware scheduler 19 1.6 agc 9. namei() strategic changes 20 1.1 agc 21 1.6 agc We currently expect to branch 6.0 in the March 2010 timeframe, with a view 22 1.6 agc to a 6.0 release later in 2010. 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 1.6 agc 2. Better Kernel Module Support 42 1.6 agc ------------------------------- 43 1.6 agc 44 1.6 agc Starting with 5.99.2, the kernel support for modules was enhanced by 45 1.6 agc ad, and GENERIC was switched over to be a MODULAR kernel. Support 46 1.6 agc from booting from modules, like ffs, was introduced at the same time. 47 1.6 agc Some work has been done by Luke Mewburn in this area to define module 48 1.6 agc locations and paths so that effective kernel development can be done 49 1.6 agc using modules. 50 1.6 agc 51 1.6 agc Responsible: ad, lukem 52 1.6 agc 53 1.7 agc 3. Full kernel preemption for real-time threads on non-x86 54 1.7 agc ---------------------------------------------------------- 55 1.5 agc 56 1.7 agc With the revamp of the kernel concurrency model, much of the kernel is 57 1.7 agc fully multi-threaded and can therefore be preempted at any time. In 58 1.7 agc support of lower context switch and dispatch times for real-time 59 1.7 agc threads, full kernel preemption is being implemented. This has been 60 1.7 agc implemented already for i386 and x86_64 (and is in 5.0), but needs to 61 1.7 agc be extended to support the ARM, MIPS and SuperH ports. 62 1.7 agc 63 1.7 agc Responsible: rmind 64 1.5 agc 65 1.6 agc 4. POSIX shared memory 66 1.6 agc ---------------------- 67 1.1 agc 68 1.1 agc Implement POSIX shared memory facilities, which can be used to create the 69 1.1 agc shared memory objects and add the memory locations to the address space of 70 1.1 agc a process. 71 1.1 agc 72 1.1 agc Responsible: rmind 73 1.1 agc 74 1.6 agc 5. Incremental namei improvements, Phase 1 75 1.6 agc ------------------------------------------ 76 1.1 agc 77 1.6 agc In NetBSD 5.99.15, some changes were made to split the namei() routine 78 1.6 agc up into logical parts, so that changes can be made to the constituent 79 1.7 agc parts in a less intrusive way. This is in the repository now, and will 80 1.7 agc be in 6.0. 81 1.1 agc 82 1.1 agc Responsible: dholland 83 1.1 agc 84 1.6 agc 6. Better resource controls 85 1.6 agc --------------------------- 86 1.1 agc 87 1.1 agc A resource provisioning and control framework that extends beyond the 88 1.1 agc traditional Unix process limits. 89 1.1 agc 90 1.6 agc 7. Improved observability: online crashdumps, remote debugging 91 1.6 agc -------------------------------------------------------------- 92 1.1 agc 93 1.1 agc XXX crashdumps while the system is running 94 1.1 agc XXX firewire support in libkvm 95 1.1 agc 96 1.6 agc 8. Processor and cache topology aware scheduler 97 1.6 agc ----------------------------------------------- 98 1.1 agc 99 1.1 agc Implement the detection of the topology of the processors and caches. 100 1.1 agc Improve the scheduler to make decisions about thread migration 101 1.1 agc according to the topology, to get better thread affinity and less 102 1.1 agc cache thrashing, and thus improve overall performance in modern SMP 103 1.1 agc systems. 104 1.1 agc 105 1.1 agc Responsible: rmind 106 1.1 agc 107 1.6 agc 9. Incremental namei improvements, Phase 2 108 1.6 agc ------------------------------------------ 109 1.1 agc 110 1.7 agc Building on the namei() split which was introduced in 5.99.15 (see (5) 111 1.7 agc above), further changes will be introduced: see the changes to namei 112 1.7 agc outlined in Message-ID: <20080319053709.GB3951 (a] netbsd.org> for more 113 1.7 agc information. This will simplify the locking and behavior of namei() 114 1.7 agc calls within the kernel to resolve path names within file systems. 115 1.1 agc 116 1.1 agc Responsible: dholland 117 1.1 agc 118 1.1 agc 119 1.1 agc 120 1.5 agc Alistair Crooks 121 1.7 agc Mon 21 Sep 2009 08:39:16 BST 122
Indexes created Wed Sep 24 05:09:52 GMT 2025