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xfrm: avoid spinlock in get_acqseq() used by xfrm user 

Eric's version fixed it for pfkey. This one is for xfrm user.
I thought about amortizing those two get_acqseq()s but it seems
reasonable to have two of these sequence spaces for the two different
interfaces.

cheers,
jamal
commit d5168d5addbc999c94aacda8f28a4a173756a72b
Author: Jamal Hadi Salim <hadi@cyberus.ca>
Date:   Tue Feb 16 06:51:22 2010 -0500

    xfrm: avoid spinlock in get_acqseq() used by xfrm user

    This is in the same spirit as commit 28aecb9d77
    by Eric Dumazet.
    Use atomic_inc_return() in get_acqseq() to avoid taking a spinlock

    Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
jamal 2010-02-16 02:01:22 +00:00 committed by David S. Miller
parent e06d41d09f
commit 6836b9bdd9
1 changed files with 5 additions and 5 deletions
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10
net/xfrm/xfrm_state.c
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@ -1462,12 +1462,12 @@ EXPORT_SYMBOL(xfrm_find_acq_byseq);
u32 xfrm_get_acqseq(void)
{
u32 res;
static u32 acqseq;
static DEFINE_SPINLOCK(acqseq_lock);
static atomic_t acqseq;
do {
res = atomic_inc_return(&acqseq);
} while (!res);
spin_lock_bh(&acqseq_lock);
res = (++acqseq ? : ++acqseq);
spin_unlock_bh(&acqseq_lock);
return res;
}
EXPORT_SYMBOL(xfrm_get_acqseq);