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.) Reviewed-by: David Vrabel <[email protected]> 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 | 45 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 6 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 9c479fe40459..96bb4a7a626d 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -45,6 +45,7 @@ #include <linux/vmalloc.h> #include <linux/module.h> #include <linux/gfp.h> +#include <linux/oom.h> #include <linux/memblock.h> #include <linux/seq_file.h> #include <linux/crash_dump.h> @@ -854,18 +855,34 @@ static void xen_pgd_pin(struct mm_struct *mm) */ void xen_mm_pin_all(void) { - struct page *page; + struct task_struct *g; + rcu_read_lock(); /* Task list walk */ spin_lock(&pgd_lock); - list_for_each_entry(page, &pgd_list, lru) { + for_each_process(g) { + struct task_struct *p; + struct mm_struct *mm; + struct page *page; + pgd_t *pgd; + + p = find_lock_task_mm(g); + if (!p) + continue; + + mm = p->mm; + pgd = mm->pgd; + page = virt_to_page(pgd); + if (!PagePinned(page)) { - __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page)); + __xen_pgd_pin(&init_mm, pgd); SetPageSavePinned(page); } + task_unlock(p); } spin_unlock(&pgd_lock); + rcu_read_unlock(); } /* @@ -968,19 +985,35 @@ static void xen_pgd_unpin(struct mm_struct *mm) */ void xen_mm_unpin_all(void) { - struct page *page; + struct task_struct *g; + rcu_read_lock(); /* Task list walk */ spin_lock(&pgd_lock); - list_for_each_entry(page, &pgd_list, lru) { + for_each_process(g) { + struct task_struct *p; + struct mm_struct *mm; + struct page *page; + pgd_t *pgd; + + p = find_lock_task_mm(g); + if (!p) + continue; + + mm = p->mm; + pgd = mm->pgd; + page = virt_to_page(pgd); + if (PageSavePinned(page)) { BUG_ON(!PagePinned(page)); - __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(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/
