FreeBSD source tree https://cgit-dev.freebsd.org/src/atom?h=releng%2F5.3 2004-08-02T00:18:36Z 2004-08-02T00:18:36Z Brian Feldman green@FreeBSD.org 2004-08-02T00:18:36Z urn:sha1:b23f72e98ae8164c07be4b3780a0b83e094844cf so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work. 2004-07-30T11:08:02Z Doug Rabson dfr@FreeBSD.org 2004-07-30T11:08:02Z urn:sha1:874f013517ffdfe671b963e792c867bb47c90405 Submitted by: nvidia 2004-07-28T18:23:08Z Alan Cox alc@FreeBSD.org 2004-07-28T18:23:08Z urn:sha1:56e0670fdc7a52b9984a90f6a748ba010c0b79aa vm/vm_object.c revision 1.88) and vm_object_sync() (originating in vm/vm_map.c revision 1.36): When descending a chain of backing objects, both use the wrong object's backing offset. Consequently, both may operate on the wrong pages. Quoting Matt, "This could be responsible for all of the sporatic madvise oddness that has been reported over the years." Reviewed by: Matt Dillon 2004-07-25T19:28:10Z Alan Cox alc@FreeBSD.org 2004-07-25T19:28:10Z urn:sha1:9b45f81502ea32ca9e5602a757393b250b4a0f1c 2004-07-25T07:48:47Z Alan Cox alc@FreeBSD.org 2004-07-25T07:48:47Z urn:sha1:57a21aba930b1b31247f3b74d84334cd5dd90d9b 2004-07-22T19:44:49Z Alan Cox alc@FreeBSD.org 2004-07-22T19:44:49Z urn:sha1:5285558ac2d0c7bb889d962c3d270463ee921ce0 kmem_alloc_pageable(). The difference between these is that an errant memory access to the zone will be detected sooner with kmem_alloc_nofault(). The following changes serve to eliminate the following lock-order reversal reported by witness: 1st 0xc1a3c084 vm object (vm object) @ vm/swap_pager.c:1311 2nd 0xc07acb00 swap_pager swhash (swap_pager swhash) @ vm/swap_pager.c:1797 3rd 0xc1804bdc vm object (vm object) @ vm/uma_core.c:931 There is no potential deadlock in this case. However, witness is unable to recognize this because vm objects used by UMA have the same type as ordinary vm objects. To remedy this, we make the following changes: - Add a mutex type argument to VM_OBJECT_LOCK_INIT(). - Use the mutex type argument to assign distinct types to special vm objects such as the kernel object, kmem object, and UMA objects. - Define a static swap zone object for use by UMA. (Only static objects are assigned a special mutex type.) 2004-06-28T20:26:35Z Tor Egge tegge@FreeBSD.org 2004-06-28T20:26:35Z urn:sha1:9174ca7ba352135f98a6430dc3b09a4740948bce vm objects shadowing source in vm_object_shadow(). This closes a race where vm_object_collapse() could be called with a partially uninitialized object argument causing symptoms that looked like hardware problems, e.g. signal 6, 10, 11 or a /bin/sh busy-waiting for a nonexistant child process. 2004-05-25T18:40:53Z Dag-Erling Smørgrav des@FreeBSD.org 2004-05-25T18:40:53Z urn:sha1:c53f7ace3a6010a0a99b4bffa65139c74a0cb5c1 semantics but provide a sysctl knob for reverting to old ones. 2004-04-06T20:15:37Z Warner Losh imp@FreeBSD.org 2004-04-06T20:15:37Z urn:sha1:05eb3785e755044e8f30f064b5be4fe1ac788dbd per letter dated July 22, 1999. Approved by: core 2004-03-08T03:54:36Z Alan Cox alc@FreeBSD.org 2004-03-08T03:54:36Z urn:sha1:a7d8612155be0dd2ed8d2e475b599da3d7f34645 vm_object_deallocate() so that it doesn't spin forever either. Submitted by: bde