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From: Alexander Duyck <alexander.duyck@gmail.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: rkrcmar@redhat.com, alexander.h.duyck@linux.intel.com,
	x86@kernel.org, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
	pbonzini@redhat.com, tglx@linutronix.de,
	akpm@linux-foundation.org
Subject: [RFC PATCH 1/4] madvise: Expose ability to set dontneed from kernel
Date: Mon, 04 Feb 2019 10:15:40 -0800
Message-ID: <20190204181540.12095.87973.stgit@localhost.localdomain> (raw)
In-Reply-To: <20190204181118.12095.38300.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

In order to enable a KVM hypervisor to notify the host that a guest has
freed its pages we will need to have a mechanism to update the virtual
memory associated with the guest. In order to expose this functionality I
am adding a new function do_madvise_dontneed that can be used to indicate
a region that a given VM is done with.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
 include/linux/mm.h |    2 ++
 mm/madvise.c       |   13 ++++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index e04396375cf9..eb668a5b4b4f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2840,5 +2840,7 @@ static inline bool page_is_guard(struct page *page)
 static inline void setup_nr_node_ids(void) {}
 #endif
 
+int do_madvise_dontneed(unsigned long start, size_t len_in);
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MM_H */
diff --git a/mm/madvise.c b/mm/madvise.c
index 21a7881a2db4..8730f7e0081a 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -799,7 +799,7 @@ static int madvise_inject_error(int behavior,
  *  -EBADF  - map exists, but area maps something that isn't a file.
  *  -EAGAIN - a kernel resource was temporarily unavailable.
  */
-SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
+static int do_madvise(unsigned long start, size_t len_in, int behavior)
 {
 	unsigned long end, tmp;
 	struct vm_area_struct *vma, *prev;
@@ -894,3 +894,14 @@ static int madvise_inject_error(int behavior,
 
 	return error;
 }
+
+SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
+{
+	return do_madvise(start, len_in, behavior);
+}
+
+int do_madvise_dontneed(unsigned long start, size_t len_in)
+{
+	return do_madvise(start, len_in, MADV_DONTNEED);
+}
+EXPORT_SYMBOL_GPL(do_madvise_dontneed);


  reply index

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-04 18:15 [RFC PATCH 0/4] kvm: Report unused guest pages to host Alexander Duyck
2019-02-04 18:15 ` Alexander Duyck [this message]
2019-02-04 18:15 ` [RFC PATCH 2/4] kvm: Add host side support for free memory hints Alexander Duyck
2019-02-10  0:44   ` Michael S. Tsirkin
2019-02-11 17:34     ` Alexander Duyck
2019-02-11 17:36       ` Michael S. Tsirkin
2019-02-11 17:41     ` Dave Hansen
2019-02-11 17:48       ` Michael S. Tsirkin
2019-02-11 18:30         ` Alexander Duyck
2019-02-11 19:24           ` Michael S. Tsirkin
2019-02-04 18:15 ` [RFC PATCH 3/4] kvm: Add guest " Alexander Duyck
2019-02-04 19:44   ` Dave Hansen
2019-02-04 20:42     ` Alexander Duyck
2019-02-04 23:00   ` Nadav Amit
2019-02-04 23:37     ` Alexander Duyck
2019-02-05  0:03       ` Nadav Amit
2019-02-05  0:16         ` Alexander Duyck
2019-02-05  1:46           ` Nadav Amit
2019-02-05 18:09             ` Alexander Duyck
2019-02-07 18:21   ` Luiz Capitulino
2019-02-07 18:44     ` Alexander Duyck
2019-02-07 20:02       ` Luiz Capitulino
2019-02-08 21:05       ` Nitesh Narayan Lal
2019-02-08 21:31         ` Alexander Duyck
2019-02-10  0:49   ` Michael S. Tsirkin
2019-02-11 16:31     ` Alexander Duyck
2019-02-11 17:36       ` Michael S. Tsirkin
2019-02-11 18:10         ` Alexander Duyck
2019-02-11 19:54           ` Michael S. Tsirkin
2019-02-11 21:00             ` Alexander Duyck
2019-02-11 22:52               ` Michael S. Tsirkin
     [not found]                 ` <94462313ccd927d25675f69de459456cf066c1a2.camel@linux.intel.com>
2019-02-12  0:34                   ` Michael S. Tsirkin
2019-02-11 17:48     ` Dave Hansen
2019-02-11 17:58       ` Michael S. Tsirkin
2019-02-11 18:19         ` Dave Hansen
2019-02-11 19:56           ` Michael S. Tsirkin
2019-02-04 18:15 ` [RFC PATCH 4/4] mm: Add merge page notifier Alexander Duyck
2019-02-04 19:40   ` Dave Hansen
2019-02-04 19:51     ` Alexander Duyck
2019-02-10  0:57   ` Michael S. Tsirkin
2019-02-11 13:30     ` Nitesh Narayan Lal
2019-02-11 14:17       ` Michael S. Tsirkin
2019-02-11 16:24         ` Nitesh Narayan Lal
2019-02-11 17:41           ` Michael S. Tsirkin
2019-02-11 18:09             ` Nitesh Narayan Lal
2019-02-11  6:40   ` Aaron Lu
2019-02-11 15:58     ` Alexander Duyck
2019-02-12  2:09       ` Aaron Lu
2019-02-12 17:20         ` Alexander Duyck
2019-02-04 18:19 ` [RFC PATCH QEMU] i386/kvm: Enable paravirtual unused page hint mechanism Alexander Duyck
2019-02-05 17:25 ` [RFC PATCH 0/4] kvm: Report unused guest pages to host Nitesh Narayan Lal
2019-02-05 18:43   ` Alexander Duyck
2019-02-07 14:48 ` Nitesh Narayan Lal
2019-02-07 16:56   ` Alexander Duyck
2019-02-10  0:51 ` Michael S. Tsirkin

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