Differential D20833
factor out common wiring code Authored by dougm on Jul 2 2019, 7:17 AM. Tags None Referenced Files
Details vm_map_unwire and vm_map_wire_locked have substantial code duplication in the attempt to get the first or next entry not in an IN_TRANSITION state. Define vm_map_entry_in_transition to reduce, but not eliminate entirely, that code duplication. No changes outside of the wiring/unwiring code. Tested by: pho Compiles and boots. Passed 14 hours of testing by Peter Holm.
Diff Detail
Event TimelineThere are a very large number of changes, so older changes are hidden. Show Older Changes Comment Actions Fatal trap 12: page fault while in kernel mode cpuid = 0; current process = 4000 (tmlock) interrupt enabled, fault virtual address = 0x20 stack pointer = 0x28:0xfffffe00ad822860 resume, IOPL = 0 current process = 4002 (tmlock) code segment = base 0x0, limit 0xfffff, type 0x1b code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, long 1, def32 0, gran 1 trap number = 12 panic: page fault cpuid = 11 time = 1562057287 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00ac311520 vpanic() at vpanic+0x19d/frame 0xfffffe00ac311570 panic() at panic+0x43/frame 0xfffffe00ac3115d0 trap_fatal() at trap_fatal+0x39c/frame 0xfffffe00ac311630 trap_pfault() at trap_pfault+0x62/frame 0xfffffe00ac311680 trap() at trap+0x2b4/frame 0xfffffe00ac311790 calltrap() at calltrap+0x8/frame 0xfffffe00ac311790 --- trap 0xc, rip = 0xffffffff80f0db15, rsp = 0xfffffe00ac311860, rbp = 0xfffffe00ac311910 --- vm_map_wire_locked() at vm_map_wire_locked+0x155/frame 0xfffffe00ac311910 vm_map_wire() at vm_map_wire+0x40/frame 0xfffffe00ac311940 kern_mlock() at kern_mlock+0x179/frame 0xfffffe00ac311990 amd64_syscall() at amd64_syscall+0x291/frame 0xfffffe00ac311ab0 Comment Actions Resolve conflicts with parts already checked in. Drop some goto-elimination in vm_map_wire_locked.
Comment Actions I would refactor this differently. I would create a helper function to handle the "in transition" case, in other words, the body of the following "if" statement. if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
/*
* We have not yet clipped the entry.
*/
...
}
Comment Actions Add a locked-assertion.
Comment Actions The motivation for this change is that I was working on another change that would do something to every function that simplified entries, and when I got to the wiring/unwiring functions, I found that it was hard to do and that I'd have to do it twice. So I concocted this patch so that I'd only have to do it once. I'm sorry that it seems I just mess with your code for no real purpose other than to annoy you. Comment Actions Came across this panic: 20190708 06:25:35 all (313/652): sort.sh swp_pager_getswapspace(8): failed swp_pager_getswapspace(4): failed swp_pager_getswapspace(32): failed swp_pager_getswapspace(32): failed swp_pager_getswapspace(32): failed Jul 8 06:32:26 mercat1 kernel: pid 72536 (sort), jid 0, uid 0, was killed: out of swap space swp_pager_getswapspace(18): failed panic: freeing free block: ffff40, size 8, mask 1 cpuid = 9 time = 1562560350 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe10a12b8270 vpanic() at vpanic+0x19d/frame 0xfffffe10a12b82c0 panic() at panic+0x43/frame 0xfffffe10a12b8320 blst_meta_free() at blst_meta_free+0x12b/frame 0xfffffe10a12b8360 blst_meta_free() at blst_meta_free+0x102/frame 0xfffffe10a12b83a0 blst_meta_free() at blst_meta_free+0x102/frame 0xfffffe10a12b83e0 blst_meta_free() at blst_meta_free+0x102/frame 0xfffffe10a12b8420 blst_meta_free() at blst_meta_free+0x102/frame 0xfffffe10a12b8460 blist_free() at blist_free+0x2e/frame 0xfffffe10a12b8480 swp_pager_freeswapspace() at swp_pager_freeswapspace+0x8a/frame 0xfffffe10a12b84a0 swp_pager_meta_free_all() at swp_pager_meta_free_all+0xbb/frame 0xfffffe10a12b84f0 swap_pager_dealloc() at swap_pager_dealloc+0x115/frame 0xfffffe10a12b8510 vm_object_terminate() at vm_object_terminate+0x27b/frame 0xfffffe10a12b8560 vm_object_deallocate() at vm_object_deallocate+0x412/frame 0xfffffe10a12b85c0 vm_map_process_deferred() at vm_map_process_deferred+0x7f/frame 0xfffffe10a12b85e0 vm_map_remove() at vm_map_remove+0xc6/frame 0xfffffe10a12b8610 vmspace_exit() at vmspace_exit+0xd3/frame 0xfffffe10a12b8650 exit1() at exit1+0x5ad/frame 0xfffffe10a12b86c0 sigexit() at sigexit+0xdaf/frame 0xfffffe10a12b89a0 postsig() at postsig+0x336/frame 0xfffffe10a12b8a70 ast() at ast+0x4c7/frame 0xfffffe10a12b8ab0 doreti_ast() at doreti_ast+0x1f/frame 0x7fffffffded0 Comment Actions The obvious questions are: Comment Actions I currently working in getting some gdb info from the current kernel. I'll then try with a pristine r349777 and then go back in time. Note that this is a "options DEBUG_MEMGUARD" build. Comment Actions So, this is unrelated to D20833. panic: freeing free block: ffff40, size 16, mask 1 cpuid = 7 time = 1562577077 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe102d97e080 vpanic() at vpanic+0x19d/frame 0xfffffe102d97e0d0 panic() at panic+0x43/frame 0xfffffe102d97e130 blst_leaf_free() at blst_leaf_free+0x7c/frame 0xfffffe102d97e160 blst_meta_free() at blst_meta_free+0x44/frame 0xfffffe102d97e1c0 blst_meta_free() at blst_meta_free+0x158/frame 0xfffffe102d97e220 blst_meta_free() at blst_meta_free+0x158/frame 0xfffffe102d97e280 blst_meta_free() at blst_meta_free+0x158/frame 0xfffffe102d97e2e0 blst_meta_free() at blst_meta_free+0x158/frame 0xfffffe102d97e340 blist_free() at blist_free+0xa1/frame 0xfffffe102d97e370 swp_pager_freeswapspace() at swp_pager_freeswapspace+0xb0/frame 0xfffffe102d97e3a0 swp_pager_update_freerange() at swp_pager_update_freerange+0x52/frame 0xfffffe102d97e3d0 swp_pager_meta_free_all() at swp_pager_meta_free_all+0xdc/frame 0xfffffe102d97e410 swap_pager_dealloc() at swap_pager_dealloc+0x20d/frame 0xfffffe102d97e440 vm_object_terminate() at vm_object_terminate+0x2a5/frame 0xfffffe102d97e490 vm_object_deallocate() at vm_object_deallocate+0x83b/frame 0xfffffe102d97e500 vm_map_entry_deallocate() at vm_map_entry_deallocate+0x2f/frame 0xfffffe102d97e530 vm_map_process_deferred() at vm_map_process_deferred+0x172/frame 0xfffffe102d97e570 _vm_map_unlock() at _vm_map_unlock+0x7a/frame 0xfffffe102d97e5a0 vm_map_remove() at vm_map_remove+0xbe/frame 0xfffffe102d97e5e0 vmspace_dofree() at vmspace_dofree+0x3f/frame 0xfffffe102d97e610 vmspace_exit() at vmspace_exit+0x154/frame 0xfffffe102d97e650 exit1() at exit1+0x5ad/frame 0xfffffe102d97e6c0 sigexit() at sigexit+0xdaf/frame 0xfffffe102d97e9a0 postsig() at postsig+0x336/frame 0xfffffe102d97ea70 ast() at ast+0x4c7/frame 0xfffffe102d97eab0 doreti_ast() at doreti_ast+0x1f/frame 0x7fffffffded0 KDB: enter: panic [ thread pid 3567 tid 100246 ] Stopped at kdb_enter+0x3b: movq $0,kdb_why db> x/s version version: FreeBSD 13.0-CURRENT #3 r349777: Mon Jul 8 10:58:08 CEST 2019\012 pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/MEMGUARD\012 db> I have updated sort.txt with some debug info. I'll attempt a binary commit search for this problem.
Comment Actions Act on reviewer feedback.
Comment Actions A have completed a full stress2 test of D20833.59786.diff without seeing any problems. Comment Actions I don't see any correctness issues with this version.
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