From patchwork Thu Jan 13 12:53:08 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 475891 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p0DCsHjS032539 for ; Thu, 13 Jan 2011 12:54:17 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756723Ab1AMMxs (ORCPT ); Thu, 13 Jan 2011 07:53:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64458 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202Ab1AMMxq (ORCPT ); Thu, 13 Jan 2011 07:53:46 -0500 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id p0DCrAEq011854 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 13 Jan 2011 07:53:10 -0500 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p0DCr90k017342; Thu, 13 Jan 2011 07:53:09 -0500 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 13519) id E803518D3E9; Thu, 13 Jan 2011 14:53:08 +0200 (IST) Date: Thu, 13 Jan 2011 14:53:08 +0200 From: Gleb Natapov To: Linus Torvalds Cc: Rik van Riel , Avi Kivity , Marcelo Tosatti , linux-kernel , KVM list Subject: Re: [GIT PULL] KVM updates for the 2.6.38 merge window Message-ID: <20110113125308.GJ14750@redhat.com> References: <4D2ACFA7.6000502@redhat.com> <4D2C21FE.3000406@redhat.com> <4D2E1010.4080706@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Thu, 13 Jan 2011 12:54:17 +0000 (UTC) diff --git a/include/linux/mm.h b/include/linux/mm.h index dc83565..d78e9e7 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -859,6 +859,9 @@ extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void * int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas); +int get_user_pages_nowait(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, int nr_pages, int write, int force, + struct page **pages, struct vm_area_struct **vmas); int get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages); struct page *get_dump_page(unsigned long addr); @@ -1416,6 +1419,8 @@ struct page *follow_page(struct vm_area_struct *, unsigned long address, #define FOLL_GET 0x04 /* do get_page on page */ #define FOLL_DUMP 0x08 /* give error on hole if it would be zero */ #define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */ +#define FOLL_RETRY 0x20 /* if disk transfer is needed release mmap_sem and return error */ +#define FOLL_NOWAIT 0x40 /* if disk transfer is needed return error without releasing mmap_sem */ typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/memory.c b/mm/memory.c index 02e48aa..0a3d3b5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1443,8 +1443,12 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, int ret; ret = handle_mm_fault(mm, vma, start, - (foll_flags & FOLL_WRITE) ? - FAULT_FLAG_WRITE : 0); + ((foll_flags & FOLL_WRITE) ? + FAULT_FLAG_WRITE : 0) | + ((foll_flags & FOLL_RETRY) ? + FAULT_FLAG_ALLOW_RETRY : 0) | + ((foll_flags & FOLL_NOWAIT) ? + FAULT_FLAG_RETRY_NOWAIT : 0)); if (ret & VM_FAULT_ERROR) { if (ret & VM_FAULT_OOM) @@ -1460,6 +1464,9 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, else tsk->min_flt++; + if (ret & VM_FAULT_RETRY) + return i ? i : -EFAULT; + /* * The VM_FAULT_WRITE bit tells us that * do_wp_page has broken COW when necessary, @@ -1563,6 +1570,23 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, } EXPORT_SYMBOL(get_user_pages); +int get_user_pages_nowait(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, int nr_pages, int write, int force, + struct page **pages, struct vm_area_struct **vmas) +{ + int flags = FOLL_TOUCH | FOLL_RETRY | FOLL_NOWAIT; + + if (pages) + flags |= FOLL_GET; + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); +} +EXPORT_SYMBOL(get_user_pages_nowait); + /** * get_dump_page() - pin user page in memory while writing it to core dump * @addr: user address