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.) 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) -- 2.1.4 -- 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/
