d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Eliminate the recomputation of pcb_cr3 from cpu_set_upcall(). The

Browse Source 
bcopy()ed value from the old thread is the correct value because the new
thread and the old thread will share a page table.
This commit is contained in:
alc 2009-03-22 02:33:48 +00:00
parent 793ddab6ba
commit e68330f894
2 changed files with 2 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/amd64/amd64/vm_machdep.c
View File

@ -287,7 +287,6 @@ cpu_set_upcall(struct thread *td, struct thread *td0)
* Set registers for trampoline to user mode. Leave space for the
* return address on stack. These are the kernel mode register values.
*/
pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pml4);
pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
pcb2->pcb_rbp = 0;
pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
@ -295,6 +294,7 @@ cpu_set_upcall(struct thread *td, struct thread *td0)
pcb2->pcb_rip = (register_t)fork_trampoline;
/*
* If we didn't copy the pcb, we'd need to do the following registers:
* pcb2->pcb_cr3: cloned above.
* pcb2->pcb_dr*: cloned above.
* pcb2->pcb_savefpu: cloned above.
* pcb2->pcb_onfault: cloned above (always NULL here?).

6
sys/i386/i386/vm_machdep.c
View File

@ -424,11 +424,6 @@ cpu_set_upcall(struct thread *td, struct thread *td0)
* Set registers for trampoline to user mode. Leave space for the
* return address on stack. These are the kernel mode register values.
*/
#ifdef PAE
pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt);
#else
pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir);
#endif
pcb2->pcb_edi = 0;
pcb2->pcb_esi = (int)fork_return; /* trampoline arg */
pcb2->pcb_ebp = 0;
@ -439,6 +434,7 @@ cpu_set_upcall(struct thread *td, struct thread *td0)
pcb2->pcb_gs = rgs();
/*
* If we didn't copy the pcb, we'd need to do the following registers:
* pcb2->pcb_cr3: cloned above.
* pcb2->pcb_dr*: cloned above.
* pcb2->pcb_savefpu: cloned above.
* pcb2->pcb_flags: cloned above.