The manual says that it is required and we actually have crash reports
where loads see stale data due to not having membars here.
In one case the networking does:
memset(skb, 0, offsetof(struct sk_buff, truesize));
and then some code later checks skb->nohdr for zero, but it's still
the value that was there before the memset().
Note that arch/sparc64/lib/xor.S already got this right.
Signed-off-by: David S. Miller <davem@davemloft.net>
We only need to write an invalid tag every 16 bytes,
so taking advantage of this can save many instructions
compared to the simple memset() call we make now.
A prefetching implementation is implemented for sun4u
and a block-init store version if implemented for Niagara.
The next trick is to be able to perform an init and
a copy_tsb() in parallel when growing a TSB table.
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller