From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B123DC2D0A7 for ; Fri, 4 Sep 2020 11:41:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E11F20709 for ; Fri, 4 Sep 2020 11:41:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728263AbgIDLle (ORCPT ); Fri, 4 Sep 2020 07:41:34 -0400 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:49580 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730069AbgIDLlc (ORCPT ); Fri, 4 Sep 2020 07:41:32 -0400 Received: from smtp.bitdefender.com (smtp01.buh.bitdefender.com [10.17.80.75]) by mx01.bbu.dsd.mx.bitdefender.com (Postfix) with ESMTPS id F224430747C6; Fri, 4 Sep 2020 14:31:05 +0300 (EEST) Received: from localhost.localdomain (unknown [195.189.155.252]) by smtp.bitdefender.com (Postfix) with ESMTPSA id 2140C3072786; Fri, 4 Sep 2020 14:31:05 +0300 (EEST) From: =?UTF-8?q?Adalbert=20Laz=C4=83r?= To: linux-mm@kvack.org Cc: linux-api@vger.kernel.org, Andrew Morton , Alexander Graf , Stefan Hajnoczi , Jerome Glisse , Paolo Bonzini , =?UTF-8?q?Mihai=20Don=C8=9Bu?= , Mircea Cirjaliu , Andy Lutomirski , Arnd Bergmann , Sargun Dhillon , Aleksa Sarai , Oleg Nesterov , Jann Horn , Kees Cook , Matthew Wilcox , Christian Brauner , =?UTF-8?q?Adalbert=20Laz=C4=83r?= Subject: [RESEND RFC PATCH 1/5] mm: add atomic capability to zap_details Date: Fri, 4 Sep 2020 14:31:12 +0300 Message-Id: <20200904113116.20648-2-alazar@bitdefender.com> In-Reply-To: <20200904113116.20648-1-alazar@bitdefender.com> References: <20200904113116.20648-1-alazar@bitdefender.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org From: Mircea Cirjaliu Force zap_xxx_range() functions to loop without rescheduling. Useful for unmapping memory in an atomic context, although no checks for atomic context are being made. Signed-off-by: Mircea Cirjaliu Signed-off-by: Adalbert Lazăr --- include/linux/mm.h | 6 ++++++ mm/memory.c | 11 +++++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 5a323422d783..1be4482a7b81 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1601,8 +1601,14 @@ struct zap_details { struct address_space *check_mapping; /* Check page->mapping if set */ pgoff_t first_index; /* Lowest page->index to unmap */ pgoff_t last_index; /* Highest page->index to unmap */ + bool atomic; /* Do not sleep. */ }; +static inline bool zap_is_atomic(struct zap_details *details) +{ + return (unlikely(details) && details->atomic); +} + struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte); struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, diff --git a/mm/memory.c b/mm/memory.c index f703fe8c8346..8e78fb151f8f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1056,7 +1056,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, if (pte_none(ptent)) continue; - if (need_resched()) + if (!zap_is_atomic(details) && need_resched()) break; if (pte_present(ptent)) { @@ -1159,7 +1159,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, } if (addr != end) { - cond_resched(); + if (!zap_is_atomic(details)) + cond_resched(); goto again; } @@ -1195,7 +1196,8 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, goto next; next = zap_pte_range(tlb, vma, pmd, addr, next, details); next: - cond_resched(); + if (!zap_is_atomic(details)) + cond_resched(); } while (pmd++, addr = next, addr != end); return addr; @@ -1224,7 +1226,8 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb, continue; next = zap_pmd_range(tlb, vma, pud, addr, next, details); next: - cond_resched(); + if (!zap_is_atomic(details)) + cond_resched(); } while (pud++, addr = next, addr != end); return addr;