Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753879AbbFMJul (ORCPT ); Sat, 13 Jun 2015 05:50:41 -0400 Received: from mail-wg0-f53.google.com ([74.125.82.53]:33947 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751332AbbFMJtp (ORCPT ); Sat, 13 Jun 2015 05:49:45 -0400 From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Andy Lutomirski , Andrew Morton , Denys Vlasenko , Brian Gerst , Peter Zijlstra , Borislav Petkov , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Thomas Gleixner , Waiman Long Subject: [PATCH 07/12] x86/virt/guest/xen: Remove use of pgd_list from the Xen guest code Date: Sat, 13 Jun 2015 11:49:10 +0200 Message-Id: <1434188955-31397-8-git-send-email-mingo@kernel.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1434188955-31397-1-git-send-email-mingo@kernel.org> References: <1434188955-31397-1-git-send-email-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3229 Lines: 114 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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Waiman Long Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar --- 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/