From: Jason Wang <jasowang@redhat.com>
To: Shirley Ma <mashirle@us.ibm.com>
Cc: eric.dumazet@gmail.com, mst@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, ebiederm@xmission.com,
davem@davemloft.net
Subject: Re: [V2 PATCH 2/9] macvtap: zerocopy: fix truesize underestimation
Date: Wed, 16 May 2012 11:04:14 +0800 [thread overview]
Message-ID: <4FB3192E.4030803@redhat.com> (raw)
In-Reply-To: <1337102809.8220.10.camel@oc3660625478.ibm.com>
On 05/16/2012 01:26 AM, Shirley Ma wrote:
> On Wed, 2012-05-02 at 11:41 +0800, Jason Wang wrote:
>> As the skb fragment were pinned/built from user pages, we should
>> account the page instead of length for truesize.
>>
>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>> ---
>> drivers/net/macvtap.c | 6 ++++--
>> 1 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
>> index bd4a70d..7cb2684 100644
>> --- a/drivers/net/macvtap.c
>> +++ b/drivers/net/macvtap.c
>> @@ -519,6 +519,7 @@ static int zerocopy_sg_from_iovec(struct sk_buff
>> *skb, const struct iovec *from,
>> struct page *page[MAX_SKB_FRAGS];
>> int num_pages;
>> unsigned long base;
>> + unsigned long truesize;
>>
>> len = from->iov_len - offset;
>> if (!len) {
>> @@ -533,10 +534,11 @@ static int zerocopy_sg_from_iovec(struct sk_buff
>> *skb, const struct iovec *from,
>> (num_pages> MAX_SKB_FRAGS -
>> skb_shinfo(skb)->nr_frags))
>> /* put_page is in skb free */
>> return -EFAULT;
>> + truesize = size * PAGE_SIZE;
> Here should be truesize = size * PAGE_SIZE - offset, right?
>
We get the whole user page, so need to account them all. Also this is
aligned with skb_copy_ubufs().
>> skb->data_len += len;
>> skb->len += len;
>> - skb->truesize += len;
>> - atomic_add(len,&skb->sk->sk_wmem_alloc);
>> + skb->truesize += truesize;
>> + atomic_add(truesize,&skb->sk->sk_wmem_alloc);
>> while (len) {
>> int off = base& ~PAGE_MASK;
>> int size = min_t(int, len, PAGE_SIZE - off);
>>
>>
next prev parent reply other threads:[~2012-05-16 3:04 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-02 3:41 [V2 PATCH 0/9] vhost/macvtap zeropcopy fixes Jason Wang
2012-05-02 3:41 ` [V2 PATCH 1/9] macvtap: zerocopy: fix offset calculation when building skb Jason Wang
2012-05-15 17:17 ` Shirley Ma
2012-05-02 3:41 ` [V2 PATCH 2/9] macvtap: zerocopy: fix truesize underestimation Jason Wang
2012-05-15 17:26 ` Shirley Ma
2012-05-16 3:04 ` Jason Wang [this message]
2012-05-16 15:03 ` Shirley Ma
2012-05-17 2:59 ` Jason Wang
2012-05-17 15:28 ` Shirley Ma
2012-05-18 10:10 ` Jason Wang
2012-05-18 15:22 ` Shirley Ma
2012-05-21 6:15 ` Jason Wang
2012-05-02 3:41 ` [V2 PATCH 3/9] macvtap: zerocopy: put page when fail to get all requested user pages Jason Wang
2012-05-15 17:33 ` Shirley Ma
2012-05-02 3:42 ` [V2 PATCH 4/9] macvtap: zerocopy: set SKBTX_DEV_ZEROCOPY only when skb is built successfully Jason Wang
2012-05-15 17:44 ` Shirley Ma
2012-05-16 3:17 ` Jason Wang
2012-05-02 3:42 ` [V2 PATCH 5/9] macvtap: zerocopy: validate vectors before building skb Jason Wang
2012-05-02 3:42 ` [V2 PATCH 6/9] vhost_net: zerocopy: fix possible NULL pointer dereference of vq->bufs Jason Wang
2012-05-02 3:42 ` [V2 PATCH 7/9] vhost_net: re-poll only on EAGAIN or ENOBUFS Jason Wang
2012-05-02 3:42 ` [V2 PATCH 8/9] vhost_net: zerocopy: adding and signalling immediately when fully copied Jason Wang
2012-05-02 3:42 ` [V2 PATCH 9/9] vhost: zerocopy: poll vq in zerocopy callback Jason Wang
2012-05-15 16:50 ` Shirley Ma
2012-05-16 2:58 ` Jason Wang
2012-05-16 15:10 ` Shirley Ma
2012-05-16 15:14 ` Michael S. Tsirkin
2012-05-16 17:32 ` Shirley Ma
2012-05-16 18:36 ` Michael S. Tsirkin
2012-05-16 19:08 ` Shirley Ma
2012-05-21 5:22 ` Jason Wang
2012-05-17 2:50 ` Jason Wang
2012-05-17 15:34 ` Shirley Ma
2012-05-18 9:58 ` Jason Wang
2012-05-18 15:29 ` Shirley Ma
2012-05-21 6:05 ` Jason Wang
2012-05-21 15:42 ` Shirley Ma
2012-05-21 16:12 ` Shirley Ma
2012-05-22 10:13 ` Jason Wang
2012-05-22 10:05 ` Jason Wang
2012-05-22 15:55 ` Shirley Ma
2012-05-23 10:31 ` Jason Wang
2012-05-02 5:50 ` [V2 PATCH 0/9] vhost/macvtap zeropcopy fixes Michael S. Tsirkin
2012-05-02 6:44 ` David Miller
2012-05-02 8:11 ` Michael S. Tsirkin
2012-05-02 19:40 ` Eric W. Biederman
2012-05-02 21:31 ` Michael S. Tsirkin
2012-05-02 21:54 ` Eric W. Biederman
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