diff options
| author | Martin Pieuchot <mpi@cvs.openbsd.org> | 2016-08-22 10:40:37 +0000 |
|---|---|---|
| committer | Martin Pieuchot <mpi@cvs.openbsd.org> | 2016-08-22 10:40:37 +0000 |
| commit | 6a25b69e6f269aef96612f0658bbbc71720ba6d5 (patch) | |
| tree | e44c1eacc57e10c83be792bcc800b8cc1358b7a8 /sys/net/bpf.c | |
| parent | 1fd9a929e6d2ad9f4ee609809ba4ffcdb53011a4 (diff) | |
Call csignal() and selwakeup() from a KERNEL_LOCK'd task.
This will allow us make bpf_tap() KERNEL_LOCK() free.
Discussed with dlg@ and input from guenther@
Diffstat (limited to 'sys/net/bpf.c')
| -rw-r--r-- | sys/net/bpf.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/sys/net/bpf.c b/sys/net/bpf.c index d731632a2bd..98a367b70c4 100644 --- a/sys/net/bpf.c +++ b/sys/net/bpf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: bpf.c,v 1.147 2016/08/15 07:20:14 mpi Exp $ */ +/* $OpenBSD: bpf.c,v 1.148 2016/08/22 10:40:36 mpi Exp $ */ /* $NetBSD: bpf.c,v 1.33 1997/02/21 23:59:35 thorpej Exp $ */ /* @@ -57,6 +57,8 @@ #include <sys/atomic.h> #include <sys/srp.h> #include <sys/specdev.h> +#include <sys/selinfo.h> +#include <sys/task.h> #include <net/if.h> #include <net/bpf.h> @@ -103,6 +105,7 @@ int bpf_setif(struct bpf_d *, struct ifreq *); int bpfpoll(dev_t, int, struct proc *); int bpfkqfilter(dev_t, struct knote *); void bpf_wakeup(struct bpf_d *); +void bpf_wakeup_cb(void *); void bpf_catchpacket(struct bpf_d *, u_char *, size_t, size_t, void (*)(const void *, void *, size_t), struct timeval *); void bpf_reset_d(struct bpf_d *); @@ -345,6 +348,7 @@ bpfopen(dev_t dev, int flag, int mode, struct proc *p) bd->bd_unit = unit; bd->bd_bufsize = bpf_bufsize; bd->bd_sig = SIGIO; + task_set(&bd->bd_wake_task, bpf_wakeup_cb, bd); if (flag & FNONBLOCK) bd->bd_rtout = -1; @@ -515,12 +519,29 @@ bpfread(dev_t dev, struct uio *uio, int ioflag) void bpf_wakeup(struct bpf_d *d) { - wakeup((caddr_t)d); + /* + * As long as csignal() and selwakeup() need to be protected + * by the KERNEL_LOCK() we have to delay the wakeup to + * another context to keep the hot path KERNEL_LOCK()-free. + */ + bpf_get(d); + if (!task_add(systq, &d->bd_wake_task)) + bpf_put(d); +} + +void +bpf_wakeup_cb(void *xd) +{ + struct bpf_d *d = xd; + + KERNEL_ASSERT_LOCKED(); + + wakeup(d); if (d->bd_async && d->bd_sig) - csignal(d->bd_pgid, d->bd_sig, - d->bd_siguid, d->bd_sigeuid); + csignal(d->bd_pgid, d->bd_sig, d->bd_siguid, d->bd_sigeuid); selwakeup(&d->bd_sel); + bpf_put(d); } int |