Author: jeff Date: Thu Jan 23 05:05:39 2020 New Revision: 357021 URL: https://svnweb.freebsd.org/changeset/base/357021
Log: (fault 2/9) Move map lookup into a dedicated function. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D23302 Modified: head/sys/vm/vm_fault.c Modified: head/sys/vm/vm_fault.c ============================================================================== --- head/sys/vm/vm_fault.c Thu Jan 23 05:03:34 2020 (r357020) +++ head/sys/vm/vm_fault.c Thu Jan 23 05:05:39 2020 (r357021) @@ -747,6 +747,54 @@ vm_fault_readahead(struct faultstate *fs) return (nera); } +static int +vm_fault_lookup(struct faultstate *fs) +{ + int result; + + KASSERT(!fs->lookup_still_valid, + ("vm_fault_lookup: Map already locked.")); + result = vm_map_lookup(&fs->map, fs->vaddr, fs->fault_type | + VM_PROT_FAULT_LOOKUP, &fs->entry, &fs->first_object, + &fs->first_pindex, &fs->prot, &fs->wired); + if (result != KERN_SUCCESS) { + unlock_vp(fs); + return (result); + } + + fs->map_generation = fs->map->timestamp; + + if (fs->entry->eflags & MAP_ENTRY_NOFAULT) { + panic("%s: fault on nofault entry, addr: %#lx", + __func__, (u_long)fs->vaddr); + } + + if (fs->entry->eflags & MAP_ENTRY_IN_TRANSITION && + fs->entry->wiring_thread != curthread) { + vm_map_unlock_read(fs->map); + vm_map_lock(fs->map); + if (vm_map_lookup_entry(fs->map, fs->vaddr, &fs->entry) && + (fs->entry->eflags & MAP_ENTRY_IN_TRANSITION)) { + unlock_vp(fs); + fs->entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; + vm_map_unlock_and_wait(fs->map, 0); + } else + vm_map_unlock(fs->map); + return (KERN_RESOURCE_SHORTAGE); + } + + MPASS((fs->entry->eflags & MAP_ENTRY_GUARD) == 0); + + if (fs->wired) + fs->fault_type = fs->prot | (fs->fault_type & VM_PROT_COPY); + else + KASSERT((fs->fault_flags & VM_FAULT_WIRE) == 0, + ("!fs->wired && VM_FAULT_WIRE")); + fs->lookup_still_valid = true; + + return (KERN_SUCCESS); +} + /* * Wait/Retry if the page is busy. We have to do this if the page is * either exclusive or shared busy because the vm_pager may be using @@ -807,6 +855,8 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fa fs.vaddr = vaddr; fs.m_hold = m_hold; fs.fault_flags = fault_flags; + fs.map = map; + fs.lookup_still_valid = false; faultcount = 0; nera = -1; hardfault = false; @@ -820,44 +870,13 @@ RetryFault_oom: * Find the backing store object and offset into it to begin the * search. */ - fs.map = map; - result = vm_map_lookup(&fs.map, fs.vaddr, fs.fault_type | - VM_PROT_FAULT_LOOKUP, &fs.entry, &fs.first_object, - &fs.first_pindex, &fs.prot, &fs.wired); + result = vm_fault_lookup(&fs); if (result != KERN_SUCCESS) { - unlock_vp(&fs); + if (result == KERN_RESOURCE_SHORTAGE) + goto RetryFault; return (result); } - fs.map_generation = fs.map->timestamp; - - if (fs.entry->eflags & MAP_ENTRY_NOFAULT) { - panic("%s: fault on nofault entry, addr: %#lx", - __func__, (u_long)fs.vaddr); - } - - if (fs.entry->eflags & MAP_ENTRY_IN_TRANSITION && - fs.entry->wiring_thread != curthread) { - vm_map_unlock_read(fs.map); - vm_map_lock(fs.map); - if (vm_map_lookup_entry(fs.map, fs.vaddr, &fs.entry) && - (fs.entry->eflags & MAP_ENTRY_IN_TRANSITION)) { - unlock_vp(&fs); - fs.entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; - vm_map_unlock_and_wait(fs.map, 0); - } else - vm_map_unlock(fs.map); - goto RetryFault; - } - - MPASS((fs.entry->eflags & MAP_ENTRY_GUARD) == 0); - - if (fs.wired) - fs.fault_type = fs.prot | (fs.fault_type & VM_PROT_COPY); - else - KASSERT((fs.fault_flags & VM_FAULT_WIRE) == 0, - ("!fs.wired && VM_FAULT_WIRE")); - /* * Try to avoid lock contention on the top-level object through * special-case handling of some types of page faults, specifically, @@ -890,8 +909,6 @@ RetryFault_oom: */ vm_object_reference_locked(fs.first_object); vm_object_pip_add(fs.first_object, 1); - - fs.lookup_still_valid = true; fs.m_cow = fs.m = fs.first_m = NULL; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
