On Sat, 2015-06-13 at 11:49 +0200, Ingo Molnar wrote: > xen_mm_pin_all()/unpin_all() are used to implement full guest instance > suspend/restore. It's a stop-all method that needs to iterate through > all allocated pgds in the system to fix them up for Xen's use. > > This code uses pgd_list, probably because it was an easy interface. > > But we want to remove the pgd_list, so convert the code over to walk > all tasks in the system. This is an equivalent method. > > (As I don't use Xen this is was only build tested.)
In which case it seems extra important to copy the appropriate maintainers, which I've done here. Ian. > > Cc: Andrew Morton <[email protected]> > Cc: Andy Lutomirski <[email protected]> > Cc: Borislav Petkov <[email protected]> > Cc: Brian Gerst <[email protected]> > Cc: Denys Vlasenko <[email protected]> > Cc: H. Peter Anvin <[email protected]> > Cc: Linus Torvalds <[email protected]> > Cc: Oleg Nesterov <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Waiman Long <[email protected]> > Cc: [email protected] > Signed-off-by: Ingo Molnar <[email protected]> > --- > arch/x86/xen/mmu.c | 51 ++++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 38 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c > index dd151b2045b0..70a3df5b0b54 100644 > --- a/arch/x86/xen/mmu.c > +++ b/arch/x86/xen/mmu.c > @@ -853,15 +853,27 @@ static void xen_pgd_pin(struct mm_struct *mm) > */ > void xen_mm_pin_all(void) > { > - struct page *page; > + struct task_struct *g, *p; > > - spin_lock(&pgd_lock); > + spin_lock(&pgd_lock); /* Implies rcu_read_lock() for the task list > iteration: */ > > - list_for_each_entry(page, &pgd_list, lru) { > - if (!PagePinned(page)) { > - __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page)); > - SetPageSavePinned(page); > + for_each_process_thread(g, p) { > + struct mm_struct *mm; > + struct page *page; > + pgd_t *pgd; > + > + task_lock(p); > + mm = p->mm; > + if (mm) { > + pgd = mm->pgd; > + page = virt_to_page(pgd); > + > + if (!PagePinned(page)) { > + __xen_pgd_pin(&init_mm, pgd); > + SetPageSavePinned(page); > + } > } > + task_unlock(p); > } > > spin_unlock(&pgd_lock); > @@ -967,19 +979,32 @@ static void xen_pgd_unpin(struct mm_struct *mm) > */ > void xen_mm_unpin_all(void) > { > - struct page *page; > + struct task_struct *g, *p; > > - spin_lock(&pgd_lock); > + spin_lock(&pgd_lock); /* Implies rcu_read_lock() for the task list > iteration: */ > > - list_for_each_entry(page, &pgd_list, lru) { > - if (PageSavePinned(page)) { > - BUG_ON(!PagePinned(page)); > - __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page)); > - ClearPageSavePinned(page); > + for_each_process_thread(g, p) { > + struct mm_struct *mm; > + struct page *page; > + pgd_t *pgd; > + > + task_lock(p); > + mm = p->mm; > + if (mm) { > + pgd = mm->pgd; > + page = virt_to_page(pgd); > + > + if (PageSavePinned(page)) { > + BUG_ON(!PagePinned(page)); > + __xen_pgd_unpin(&init_mm, pgd); > + ClearPageSavePinned(page); > + } > } > + task_unlock(p); > } > > spin_unlock(&pgd_lock); > + rcu_read_unlock(); > } > > static void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
