Commit 6836b9bd authored by jamal's avatar jamal Committed by David S. Miller
Browse files

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 28aecb9d


    by Eric Dumazet.
    Use atomic_inc_return() in get_acqseq() to avoid taking a spinlock
Signed-off-by: default avatarJamal Hadi Salim <hadi@cyberus.ca>
Acked-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e06d41d0
......@@ -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);
......
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