From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: [PATCH 01/17] mm: gup: add FOLL_TRIED Date: Fri, 3 Oct 2014 19:07:51 +0200 Message-ID: <1412356087-16115-2-git-send-email-aarcange@redhat.com> References: <1412356087-16115-1-git-send-email-aarcange@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1412356087-16115-1-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org To: qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org Cc: Linus Torvalds , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Hugh Dickins , Peter Feiner , "\\\"Dr. David Alan Gilbert\\\"" , Christopher Covington , Johannes Weiner , Android Kernel Team , Robert Love , Dmitry Adamushko , Neil Brown , Mike Hommey , Taras Glek , Jan Kara List-Id: linux-api@vger.kernel.org From: Andres Lagar-Cavilla Reviewed-by: Radim Kr=C4=8Dm=C3=A1=C5=99 Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Andrea Arcangeli --- include/linux/mm.h | 1 + mm/gup.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 8981cc8..0f4196a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1985,6 +1985,7 @@ static inline struct page *follow_page(struct vm_ar= ea_struct *vma, #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry= */ +#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */ =20 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/gup.c b/mm/gup.c index 91d044b..af7ea3e 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -281,6 +281,10 @@ static int faultin_page(struct task_struct *tsk, str= uct vm_area_struct *vma, fault_flags |=3D FAULT_FLAG_ALLOW_RETRY; if (*flags & FOLL_NOWAIT) fault_flags |=3D FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT; + if (*flags & FOLL_TRIED) { + VM_WARN_ON_ONCE(fault_flags & FAULT_FLAG_ALLOW_RETRY); + fault_flags |=3D FAULT_FLAG_TRIED; + } =20 ret =3D handle_mm_fault(mm, vma, address, fault_flags); if (ret & VM_FAULT_ERROR) { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org