Hi all,
I am currently using a sendpage interface in linux kernel
2.6.14.Earlier i was using sendmsg interface but switched to sendpage
to avoid data copying.
On using sendpage, i have encountered a problem of memory leak due to
page count not getting decremented.
On looking at the linux source code for kernel 2.6.14 i found out that
in the following code a call is being made to "get_page" which
increments the page reference count, but there is no corresponding
"put_page" or other function which decrement the page count.
558 if (can_coalesce)
559 skb_shinfo(skb)->frags[i-1].size += copy;
560 } else {
561 get_page(page);
562 skb_fill_page_desc(skb, i, page, offset, copy);
563 }
Because of this "get_page" call, page count is getting incremented and
since visibly there is no call for decrementing the page count, pages
are not getting freed. This is resulting in a memory leak. I have
checked out that this code is actually getting executed in my case.
Please let me know if this is a kernel bug or I am missing something.
Thanks
kSanjay
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