Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754817AbbFKOJW (ORCPT ); Thu, 11 Jun 2015 10:09:22 -0400 Received: from mail-wg0-f53.google.com ([74.125.82.53]:32776 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932974AbbFKOHt (ORCPT ); Thu, 11 Jun 2015 10:07:49 -0400 From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: linux-mml@vger.kernel.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 09/12] x86/mm/pat/32: Remove pgd_list use from the PAT code Date: Thu, 11 Jun 2015 16:07:14 +0200 Message-Id: <1434031637-9091-10-git-send-email-mingo@kernel.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1434031637-9091-1-git-send-email-mingo@kernel.org> References: <1434031637-9091-1-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: 2038 Lines: 71 The 32-bit x86 PAT code uses __set_pmd_pte() to update pmds. This uses pgd_list currently, but we don't need the global list as we can walk the task list under RCU. (This code already holds the pgd_lock.) Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Waiman Long Cc: linux-mm@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 997fc97e9072..93c134fdb398 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -438,18 +438,31 @@ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) set_pte_atomic(kpte, pte); #ifdef CONFIG_X86_32 if (!SHARED_KERNEL_PMD) { - struct page *page; + struct task_struct *g, *p; - list_for_each_entry(page, &pgd_list, lru) { + rcu_read_lock(); + + for_each_process_thread(g, p) { + spinlock_t *pgt_lock; pgd_t *pgd; pud_t *pud; pmd_t *pmd; - pgd = (pgd_t *)page_address(page) + pgd_index(address); + if (!p->mm) + continue; + + pgt_lock = &p->mm->page_table_lock; + spin_lock(pgt_lock); + + pgd = p->mm->pgd + pgd_index(address); pud = pud_offset(pgd, address); pmd = pmd_offset(pud, address); set_pte_atomic((pte_t *)pmd, pte); + + spin_unlock(pgt_lock); } + + rcu_read_unlock(); } #endif } -- 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/