Lee Jones
2021-Jul-21 14:30 UTC
[PATCH 1/1] virtio/vsock: Make vsock virtio packet buff size configurable
From: Ram Muthiah <rammuthiah at google.com>
After a virtual device has been running for some time, the SLAB
sustains ever increasing fragmentation. Contributing to this
fragmentation are the virtio packet buffer allocations which
are a drain on 64Kb compound pages. Eventually these can't be
allocated due to fragmentation.
To enable successful allocations for this packet buffer, the
packet buffer's size needs to be reduced.
In order to enable a reduction without impacting current users,
this variable is being exposed as a command line parameter.
Cc: "Michael S. Tsirkin" <mst at redhat.com>
Cc: Jason Wang <jasowang at redhat.com>
Cc: Stefan Hajnoczi <stefanha at redhat.com>
Cc: Stefano Garzarella <sgarzare at redhat.com>
Cc: "David S. Miller" <davem at davemloft.net>
Cc: Jakub Kicinski <kuba at kernel.org>
Cc: virtualization at lists.linux-foundation.org
Cc: kvm at vger.kernel.org
Cc: netdev at vger.kernel.org
Signed-off-by: Ram Muthiah <rammuthiah at google.com>
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
include/linux/virtio_vsock.h | 4 +++-
net/vmw_vsock/virtio_transport_common.c | 4 ++++
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 35d7eedb5e8e4..8c77d60a74d34 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -7,9 +7,11 @@
#include <net/sock.h>
#include <net/af_vsock.h>
+extern uint virtio_transport_max_vsock_pkt_buf_size;
+
#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 4)
#define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL
-#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64)
+#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE virtio_transport_max_vsock_pkt_buf_size
enum {
VSOCK_VQ_RX = 0, /* for host to guest data */
diff --git a/net/vmw_vsock/virtio_transport_common.c
b/net/vmw_vsock/virtio_transport_common.c
index 169ba8b72a630..d0d913afec8b6 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -26,6 +26,10 @@
/* Threshold for detecting small packets to copy */
#define GOOD_COPY_LEN 128
+uint virtio_transport_max_vsock_pkt_buf_size = 1024 * 64;
+module_param(virtio_transport_max_vsock_pkt_buf_size, uint, 0444);
+EXPORT_SYMBOL_GPL(virtio_transport_max_vsock_pkt_buf_size);
+
static const struct virtio_transport *
virtio_transport_get_ops(struct vsock_sock *vsk)
{
--
2.32.0.402.g57bb445576-goog
Stefano Garzarella
2021-Jul-22 12:55 UTC
[PATCH 1/1] virtio/vsock: Make vsock virtio packet buff size configurable
On Wed, Jul 21, 2021 at 03:30:00PM +0100, Lee Jones wrote:>From: Ram Muthiah <rammuthiah at google.com> > >After a virtual device has been running for some time, the SLAB >sustains ever increasing fragmentation. Contributing to this >fragmentation are the virtio packet buffer allocations which >are a drain on 64Kb compound pages. Eventually these can't be >allocated due to fragmentation. > >To enable successful allocations for this packet buffer, the >packet buffer's size needs to be reduced. > >In order to enable a reduction without impacting current users, >this variable is being exposed as a command line parameter. > >Cc: "Michael S. Tsirkin" <mst at redhat.com> >Cc: Jason Wang <jasowang at redhat.com> >Cc: Stefan Hajnoczi <stefanha at redhat.com> >Cc: Stefano Garzarella <sgarzare at redhat.com> >Cc: "David S. Miller" <davem at davemloft.net> >Cc: Jakub Kicinski <kuba at kernel.org> >Cc: virtualization at lists.linux-foundation.org >Cc: kvm at vger.kernel.org >Cc: netdev at vger.kernel.org >Signed-off-by: Ram Muthiah <rammuthiah at google.com> >Signed-off-by: Lee Jones <lee.jones at linaro.org> >--- > include/linux/virtio_vsock.h | 4 +++- > net/vmw_vsock/virtio_transport_common.c | 4 ++++ > 2 files changed, 7 insertions(+), 1 deletion(-) > >diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >index 35d7eedb5e8e4..8c77d60a74d34 100644 >--- a/include/linux/virtio_vsock.h >+++ b/include/linux/virtio_vsock.h >@@ -7,9 +7,11 @@ > #include <net/sock.h> > #include <net/af_vsock.h> > >+extern uint virtio_transport_max_vsock_pkt_buf_size; >+ > #define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 4) > #define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL >-#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64) >+#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE virtio_transport_max_vsock_pkt_buf_size > > enum { > VSOCK_VQ_RX = 0, /* for host to guest data */ >diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c >index 169ba8b72a630..d0d913afec8b6 100644 >--- a/net/vmw_vsock/virtio_transport_common.c >+++ b/net/vmw_vsock/virtio_transport_common.c >@@ -26,6 +26,10 @@ > /* Threshold for detecting small packets to copy */ > #define GOOD_COPY_LEN 128 > >+uint virtio_transport_max_vsock_pkt_buf_size = 1024 * 64; >+module_param(virtio_transport_max_vsock_pkt_buf_size, uint, 0444); >+EXPORT_SYMBOL_GPL(virtio_transport_max_vsock_pkt_buf_size); >+Maybe better to add an entry under sysfs similar to what Jiang proposed here: https://lists.linuxfoundation.org/pipermail/virtualization/2021-June/054769.html Thanks, Stefano