From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932488AbbIVGYh (ORCPT ); Tue, 22 Sep 2015 02:24:37 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:34735 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755491AbbIVGYP (ORCPT ); Tue, 22 Sep 2015 02:24:15 -0400 From: Ingo Molnar To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andy Lutomirski , Andrew Morton , Denys Vlasenko , Brian Gerst , Peter Zijlstra , Borislav Petkov , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Waiman Long , Thomas Gleixner Subject: [PATCH 06/11] x86/virt/guest/xen: Remove use of pgd_list from the Xen guest code Date: Tue, 22 Sep 2015 08:23:36 +0200 Message-Id: <1442903021-3893-7-git-send-email-mingo@kernel.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1442903021-3893-1-git-send-email-mingo@kernel.org> References: <1442903021-3893-1-git-send-email-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 | 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 #include #include +#include #include #include #include @@ -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