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* Fix a few bugs with NFS and mmap caused by NFS' use of b_validoffdfr1997-05-191-2/+2
| | | | | | | | and b_validend. The changes to vfs_bio.c are a bit ugly but hopefully can be tidied up later by a slight redesign. PR: kern/2573, kern/2754, kern/3046 (possibly) Reviewed by: dyson
* Commit a typo fix that's been sitting in my tree for ages, quite forgotten.peter1997-04-061-2/+2
| | | | | | | | | The typo was detected once apon a time with the -Wunused compile option. The result was that a block of code for implementing madvise(.. MADV_SEQUENTIAL..) behavior was "dead" and unused, probably negating the effect of activating the option. Reviewed by: dyson
* Fix the gdb executable modify problem. Thanks to the detective workdyson1997-04-061-9/+11
| | | | | | | | | | | | by Alan Cox <alc@cs.rice.edu>, and his description of the problem. The bug was primarily in procfs_mem, but the mistake likely happened due to the lack of vm system support for the operation. I added better support for selective marking of page dirty flags so that vm_map_pageable(wiring) will not cause this problem again. The code in procfs_mem is now less bogus (but maybe still a little so.)
* Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are notpeter1997-02-221-1/+1
| | | | ready for it yet.
* This is the kernel Lite/2 commit. There are some requisite userlanddyson1997-02-101-2/+3
| | | | | | | | | | | | | | | changes, so don't expect to be able to run the kernel as-is (very well) without the appropriate Lite/2 userland changes. The system boots and can mount UFS filesystems. Untested: ext2fs, msdosfs, NFS Known problems: Incorrect Berkeley ID strings in some files. Mount_std mounts will not work until the getfsent library routine is changed. Reviewed by: various people Submitted by: Jeffery Hsu <hsu@freebsd.org>
* Change the map entry flags from bitfields to bitmasks. Allowsdyson1997-01-161-2/+2
| | | | for some code simplification.
* Make the long-awaited change from $Id$ to $FreeBSD$jkh1997-01-141-1/+1
| | | | | | | | This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
* Undo the collapse breakage (swap space usage problem.)dyson1997-01-031-3/+1
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* Guess what? We left alot of the old collapse code that is not neededdyson1997-01-011-1/+3
| | | | | | anymore with the "full" collapse fix that we added about 1yr ago!!! The code has been removed by optioning it out for now, so we can put it back in ASAP if any problems are found.
* Superficial cleanup of comment.dyson1996-12-291-2/+2
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* Implement closer-to POSIX mlock semantics. The major difference isdyson1996-12-141-2/+69
| | | | | | | | | | that we do allow mlock to span unallocated regions (of course, not mlocking them.) We also allow mlocking of RO regions (which the old code couldn't.) The restriction there is that once a RO region is wired (mlocked), it cannot be debugged (or EVER written to.) Under normal usage, the new mlock code will be a significant improvement over our old stuff.
* Implement a new totally dynamic (up to MAXPHYS) buffer kva allocationdyson1996-11-301-8/+7
| | | | | | | | | | | | | | | scheme. Additionally, add the capability for checking for unexpected kernel page faults. The maximum amount of kva space for buffers hasn't been decreased from where it is, but it will now be possible to do so. This scheme manages the kva space similar to the buffers themselves. If there isn't enough kva space because of usage or fragementation, buffers will be reclaimed until a buffer allocation is successful. This scheme should be very resistant to fragmentation problems until/if the LFS code is fixed and uses the bogus buffer locking scheme -- but a 'fixed' LFS is not likely to use such a scheme. Now there should be NO problem allocating buffers up to MAXPHYS.
* Addition of page coloring support. Various levels of coloring are afforded.dyson1996-09-081-2/+2
| | | | | | The default level works with minimal overhead, but one can also enable full, efficient use of a 512K cache. (Parameters can be generated to support arbitrary cache sizes also.)
* Backed out the recent changes/enhancements to the VM code. Thedyson1996-07-301-6/+13
| | | | | | | problem with the 'shell scripts' was found, but there was a 'strange' problem found with a 486 laptop that we could not find. This commit backs the code back to 25-jul, and will be re-entered after the snapshot in smaller (more easily tested) chunks.
* Undo part of the scalability commit. Many of the changesdyson1996-07-281-29/+15
| | | | | in vm_fault had some performance enhancements not ready for prime time. This commit backs out some of the changes.
* This commit is meant to solve a couple of VM system problems ordyson1996-07-271-27/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | performance issues. 1) The pmap module has had too many inlines, and so the object file is simply bigger than it needs to be. Some common code is also merged into subroutines. 2) Removal of some *evil* PHYS_TO_VM_PAGE macro calls. Unfortunately, a few have needed to be added also. The removal caused the need for more vm_page_lookups. I added lookup hints to minimize the need for the page table lookup operations. 3) Removal of some bogus performance improvements, that mostly made the code more complex (tracking individual page table page updates unnecessarily). Those improvements actually hurt 386 processors perf (not that people who worry about perf use 386 processors anymore :-)). 4) Changed pv queue manipulations/structures to be TAILQ's. 5) The pv queue code has had some performance problems since day one. Some significant scalability issues are resolved by threading the pv entries from the pmap AND the physical address instead of just the physical address. This makes certain pmap operations run much faster. This does not affect most micro-benchmarks, but should help loaded system performance *significantly*. DG helped and came up with most of the solution for this one. 6) Most if not all pmap bit operations follow the pattern: pmap_test_bit(); pmap_clear_bit(); That made for twice the necessary pv list traversal. The pmap interface now supports only pmap_tc_bit type operations: pmap_[test/clear]_modified, pmap_[test/clear]_referenced. Additionally, the modified routine now takes a vm_page_t arg instead of a phys address. This eliminates a PHYS_TO_VM_PAGE operation. 7) Several rewrites of routines that contain redundant code to use common routines, so that there is a greater likelihood of keeping the cache footprint smaller.
* Properly set the PG_MAPPED and PG_WRITEABLE flags. This fixes some potentialdyson1996-07-021-2/+2
| | | | problems with vm_map_remove/vm_map_delete.
* Various bugfixes/cleanups from me and others:dyson1996-06-161-13/+19
| | | | | | | | | | | | 1) Remove potential race conditions on waking up in vm_page_free_wakeup by making sure that it is at splvm(). 2) Fix another bug in vm_map_simplify_entry. 3) Be more complete about converting from default to swap pager when an object grows to be large enough that there can be a problem with data structure allocation under low memory conditions. 4) Make some madvise code more efficient. 5) Added some comments.
* Move a case of PG_MAPPED being set before a pmap_enter(). This will likelydg1996-06-141-2/+2
| | | | | make no difference, but it will make it consistent with other uses of PG_MAPPED.
* Keep the vm_fault/vm_pageout from getting into an "infinite paging loop", bydyson1996-06-101-3/+7
| | | | | | reserving "cached" pages before waking up the pageout daemon. This will reserve the faulted page, and keep the system from thrashing itself to death given this condition.
* Adjust the threshold for blocking on movement of pages from the cachedyson1996-06-081-5/+4
| | | | | | | | | | | | | | | | | queue in vm_fault. Move the PG_BUSY in vm_fault to the correct place. Remove redundant/unnecessary code in pmap.c. Properly block on rundown of page table pages, if they are busy. I think that the VM system is in pretty good shape now, and the following individuals (among others, in no particular order) have helped with this recent bunch of bugs, thanks! If I left anyone out, I apologize! Stephen McKay, Stephen Hocking, Eric J. Chet, Dan O'Brien, James Raynard, Marc Fournier.
* Disable madvise optimizations for device pager objects (some of thedyson1996-06-011-6/+9
| | | | | | | operations don't work with FICTITIOUS pages.) Also, close a window between PG_MANAGED and pmap_enter that can mess up the accounting of the managed flag. This problem could likely cause a hold_count error for page table pages.
* This commit is dual-purpose, to fix more of the pageout daemondyson1996-05-311-1/+12
| | | | | | queue corruption problems, and to apply Gary Palmer's code cleanups. David Greenman helped with these problems also. There is still a hang problem using X in small memory machines.
* I think this covers (fixes) the last batch of freeing active/held/busy pagedyson1996-05-261-1/+3
| | | | | | problem. BY MISTAKE, the vm_page_unqueue (or equiv) was removed from the vm_fault code. Really bad things appear to happen if a page is on a queue while it is being faulted.
* Initial support for mincore and madvise. Both are almost fullydyson1996-05-191-3/+43
| | | | | supported, except madvise does not page in with MADV_WILLNEED, and MADV_DONTNEED doesn't force dirty pages out.
* This set of commits to the VM system does the following, and containdyson1996-05-181-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | contributions or ideas from Stephen McKay <syssgm@devetir.qld.gov.au>, Alan Cox <alc@cs.rice.edu>, David Greenman <davidg@freebsd.org> and me: More usage of the TAILQ macros. Additional minor fix to queue.h. Performance enhancements to the pageout daemon. Addition of a wait in the case that the pageout daemon has to run immediately. Slightly modify the pageout algorithm. Significant revamp of the pmap/fork code: 1) PTE's and UPAGES's are NO LONGER in the process's map. 2) PTE's and UPAGES's reside in their own objects. 3) TOTAL elimination of recursive page table pagefaults. 4) The page directory now resides in the PTE object. 5) Implemented pmap_copy, thereby speeding up fork time. 6) Changed the pv entries so that the head is a pointer and not an entire entry. 7) Significant cleanup of pmap_protect, and pmap_remove. 8) Removed significant amounts of machine dependent fork code from vm_glue. Pushed much of that code into the machine dependent pmap module. 9) Support more completely the reuse of already zeroed pages (Page table pages and page directories) as being already zeroed. Performance and code cleanups in vm_map: 1) Improved and simplified allocation of map entries. 2) Improved vm_map_copy code. 3) Corrected some minor problems in the simplify code. Implemented splvm (combo of splbio and splimp.) The VM code now seldom uses splhigh. Improved the speed of and simplified kmem_malloc. Minor mod to vm_fault to avoid using pre-zeroed pages in the case of objects with backing objects along with the already existant condition of having a vnode. (If there is a backing object, there will likely be a COW... With a COW, it isn't necessary to start with a pre-zeroed page.) Minor reorg of source to perhaps improve locality of ref.
* VM performance improvements, and reorder some operations in VM faultdyson1996-03-281-5/+5
| | | | | in anticipation of a fix in pmap that will allow the mlock system call to work without panicing the system.
* Set the page valid bits in fewer places, as opposed to being scattereddyson1996-03-091-5/+3
| | | | in various places.
* 1) Eliminate unnecessary bzero of UPAGES.dyson1996-03-021-43/+128
| | | | | 2) Eliminate unnecessary copying of pages during/after forks. 3) Add user map simplification.
* Eliminated many redundant vm_map_lookup operations for vm_mmap.dyson1996-01-191-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | Speed up for vfs_bio -- addition of a routine bqrelse to greatly diminish overhead for merged cache. Efficiency improvement for vfs_cluster. It used to do alot of redundant calls to cluster_rbuild. Correct the ordering for vrele of .text and release of credentials. Use the selective tlb update for 486/586/P6. Numerous fixes to the size of objects allocated for files. Additionally, fixes in the various pagers. Fixes for proper positioning of vnode_pager_setsize in msdosfs and ext2fs. Fixes in the swap pager for exhausted resources. The pageout code will not as readily thrash. Change the page queue flags (PG_ACTIVE, PG_INACTIVE, PG_FREE, PG_CACHE) into page queue indices (PQ_ACTIVE, PQ_INACTIVE, PQ_FREE, PQ_CACHE), thereby improving efficiency of several routines. Eliminate even more unnecessary vm_page_protect operations. Significantly speed up process forks. Make vm_object_page_clean more efficient, thereby eliminating the pause that happens every 30seconds. Make sequential clustered writes B_ASYNC instead of B_DELWRI even in the case of filesystems mounted async. Fix a panic with busy pages when write clustering is done for non-VMIO buffers.
* Changes to support 1Tb filesizes. Pages are now named by andyson1995-12-111-46/+49
| | | | (object,index) pair instead of (object,offset) pair.
* Untangled the vm.h include file spaghetti.dg1995-12-071-1/+9
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* Remove unused vars & funcs, make things static, protoize a little bit.phk1995-11-201-3/+1
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* Greatly simplify the msync code. Eliminate complications in vm_pageoutdyson1995-11-051-2/+2
| | | | | for msyncing. Remove a bug that manifests itself primarily on NFS (the dirty range on the buffers is not set on msync.)
* Move page fixups (pmap_clear_modify, etc) that happen after paging inputdg1995-11-021-4/+1
| | | | | | | completes out of vm_fault and into the pagers. This get rid of some redundancy and improves the architecture. Reviewed by: John Dyson <dyson>
* First phase of removing the PG_COPYONWRITE flag, and an architecturaldyson1995-10-231-9/+1
| | | | cleanup of mapping files.
* Fix argument passing to the "freeer" routine. Added some prototypes. (bde)dg1995-10-071-2/+2
| | | | | | | Moved extern declaration of swap_pager_full into swap_pager.h and out of the various files that reference it. (davidg) Submitted by: bde & davidg
* Significantly simplify the fault clustering code. After some analysis bydyson1995-09-241-114/+56
| | | | | | | David Greenman, it has been determined that the more sophisticated code only made a very minor difference in fault performance. Therefore, this code eliminates some of the complication of the fault code, decreasing the amount of CPU used to scan shadow chains.
* Fixed a typo in vm_fault_additional_pages.dyson1995-09-141-2/+2
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* Code cleanup and minor performance improvement in the faultin clusterdyson1995-09-111-33/+29
| | | | code.
* Minor performance improvements, additional prototype for additionaldyson1995-09-061-4/+5
| | | | exported symbol.
* Allow the fault code to use additional clustering info from bothdyson1995-09-041-6/+25
| | | | bmap and the swap pager. Improved fault clustering performance.
* Machine independent changes to support pre-zeroed free pages. Thisdyson1995-09-031-5/+6
| | | | significantly improves demand-zero performance.
* NOTE: libkvm, w, ps, 'top', and any other utility which depends on structdg1995-07-131-254/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
* Remove trailing whitespace.rgrimes1995-05-301-13/+13
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* Accessing pages beyond the end of a mapped file results in internaldg1995-05-181-1/+5
| | | | | | | | | | | | | inconsistencies in the VM system that eventually lead to a panic. These changes fix the behavior to conform to the behavior in SunOS, which is to deny faults to pages beyond the EOF (returning SIGBUS). Internally, this is implemented by requiring faults to be within the object size boundaries. These changes exposed another bug, namely that passing in an offset to mmap when trying to map an unnamed anonymous region also results in internal inconsistencies. In this case, the offset is forced to zero. Reviewed by: John Dyson and others
* Removed obsolete/unused variable declarations. Killed externs and includeddg1995-04-161-2/+1
| | | | appropriate include files.
* Changes from John Dyson and myself:dg1995-04-091-3/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixed remaining known bugs in the buffer IO and VM system. vfs_bio.c: Fixed some race conditions and locking bugs. Improved performance by removing some (now) unnecessary code and fixing some broken logic. Fixed process accounting of # of FS outputs. Properly handle NFS interrupts (B_EINTR). (various) Replaced calls to clrbuf() with calls to an optimized routine called vfs_bio_clrbuf(). (various FS sync) Sync out modified vnode_pager backed pages. ffs_vnops.c: Do two passes: Sync out file data first, then indirect blocks. vm_fault.c: Fixed deadly embrace caused by acquiring locks in the wrong order. vnode_pager.c: Changed to use buffer I/O system for writing out modified pages. This should fix the problem with the modification date previous not getting updated. Also dramatically simplifies the code. Note that this is going to change in the future and be implemented via VOP_PUTPAGES(). vm_object.c: Fixed a pile of bugs related to cleaning (vnode) objects. The performance of vm_object_page_clean() is terrible when dealing with huge objects, but this will change when we implement a binary tree to keep the object pages sorted. vm_pageout.c: Fixed broken clustering of pageouts. Fixed race conditions and other lockup style bugs in the scanning of pages. Improved performance.
* Explicitly set page dirty if this is a write fault - reduces calls todg1995-03-271-2/+11
| | | | pmap_is_modified() later.
* Various changes from John and myself that do the following:dg1995-03-011-67/+30
| | | | | | | | | | New functions create - vm_object_pip_wakeup and pagedaemon_wakeup that are used to reduce the actual number of wakeups. New function vm_page_protect which is used in conjuction with some new page flags to reduce the number of calls to pmap_page_protect. Minor changes to reduce unnecessary spl nesting. Rewrote vm_page_alloc() to improve readability. Various other mostly cosmetic changes.
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