0d89419319
When TCP_ZEROCOPY_RECEIVE operation has been added, I made the mistake of automatically un-mapping prior content before mapping new pages. This has the unfortunate effect of adding potentially long MMU operations (like TLB flushes) while socket lock is held. Using madvise(MADV_DONTNEED) right after pages has been used has two benefits : 1) This releases pages sooner, allowing pages to be recycled if they were part of a page pool in a NIC driver. 2) No more long unmap operations while preventing immediate processing of incoming packets. The cost of the added system call is small enough. Arjun will submit a kernel patch allowing to opt out from the unmap attempt in tcp_zerocopy_receive() Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Arjun Roy <arjunroy@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| fault-injection | ||
| ktest | ||
| kunit | ||
| nvdimm | ||
| radix-tree | ||
| scatterlist | ||
| selftests | ||
| vsock | ||