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Reduce the vnet_set module size of ip_mroute to allow loading as a module.

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With VIMAGE kernels modules get special treatment as they need
to also keep the original values and make copies for each instance.
For that a few pages of vnet modspace are provided and the
kernel-linker and the VNET framework know how to deal with things.
When the modspace is (almost) full, other modules which would
overflow the modspace cannot be loaded and kldload will fail.

ip_mroute uses a lot of variable space, mostly be four big arrays:
set_vnet 0000000000000510 vnet_entry_multicast_register_if
set_vnet 0000000000000700 vnet_entry_viftable
set_vnet 0000000000002000 vnet_entry_bw_meter_timers
set_vnet 0000000000002800 vnet_entry_bw_upcalls

Dynamically malloc the three big ones for each instance we need
and free them again on vnet teardown (the 4th is an ifnet).
That way they only need module space for a single pointer and
allow a lot more modules using virtualized variables to be loaded
on a VNET kernel.

PR:		206583
Reviewed by:	hselasky, kp
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D22443
This commit is contained in:
Bjoern A. Zeeb 2019-11-19 15:38:55 +00:00
parent b2b7a4b2ca
commit 1a117215c7
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=354857
1 changed files with 20 additions and 6 deletions
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26
sys/netinet/ip_mroute.c
View File

@ -179,10 +179,14 @@ static struct mtx mfc_mtx;
VNET_DEFINE_STATIC(vifi_t, numvifs);
#define V_numvifs VNET(numvifs)
VNET_DEFINE_STATIC(struct vif, viftable[MAXVIFS]);
VNET_DEFINE_STATIC(struct vif *, viftable);
#define V_viftable VNET(viftable)
/*
* No one should be able to "query" this before initialisation happened in
* vnet_mroute_init(), so we should still be fine.
*/
SYSCTL_OPAQUE(_net_inet_ip, OID_AUTO, viftable, CTLFLAG_VNET | CTLFLAG_RD,
&VNET_NAME(viftable), sizeof(V_viftable), "S,vif[MAXVIFS]",
&VNET_NAME(viftable), sizeof(*V_viftable) * MAXVIFS, "S,vif[MAXVIFS]",
"IPv4 Multicast Interfaces (struct vif[MAXVIFS], netinet/ip_mroute.h)");
static struct mtx vif_mtx;
@ -210,7 +214,7 @@ static MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters");
* expiration time. Periodically, the entries are analysed and processed.
*/
#define BW_METER_BUCKETS 1024
VNET_DEFINE_STATIC(struct bw_meter*, bw_meter_timers[BW_METER_BUCKETS]);
VNET_DEFINE_STATIC(struct bw_meter **, bw_meter_timers);
#define V_bw_meter_timers VNET(bw_meter_timers)
VNET_DEFINE_STATIC(struct callout, bw_meter_ch);
#define V_bw_meter_ch VNET(bw_meter_ch)
@ -220,7 +224,7 @@ VNET_DEFINE_STATIC(struct callout, bw_meter_ch);
* Pending upcalls are stored in a vector which is flushed when
* full, or periodically
*/
VNET_DEFINE_STATIC(struct bw_upcall, bw_upcalls[BW_UPCALLS_MAX]);
VNET_DEFINE_STATIC(struct bw_upcall *, bw_upcalls);
#define V_bw_upcalls VNET(bw_upcalls)
VNET_DEFINE_STATIC(u_int, bw_upcalls_n); /* # of pending upcalls */
#define V_bw_upcalls_n VNET(bw_upcalls_n)
@ -764,7 +768,7 @@ X_ip_mrouter_done(void)
bzero(V_nexpire, sizeof(V_nexpire[0]) * mfchashsize);
V_bw_upcalls_n = 0;
bzero(V_bw_meter_timers, sizeof(V_bw_meter_timers));
bzero(V_bw_meter_timers, BW_METER_BUCKETS * sizeof(*V_bw_meter_timers));
MFC_UNLOCK();
@ -2802,7 +2806,14 @@ vnet_mroute_init(const void *unused __unused)
{
V_nexpire = malloc(mfchashsize, M_MRTABLE, M_WAITOK|M_ZERO);
bzero(V_bw_meter_timers, sizeof(V_bw_meter_timers));
V_viftable = mallocarray(MAXVIFS, sizeof(*V_viftable),
M_MRTABLE, M_WAITOK|M_ZERO);
V_bw_meter_timers = mallocarray(BW_METER_BUCKETS,
sizeof(*V_bw_meter_timers), M_MRTABLE, M_WAITOK|M_ZERO);
V_bw_upcalls = mallocarray(BW_UPCALLS_MAX, sizeof(*V_bw_upcalls),
M_MRTABLE, M_WAITOK|M_ZERO);
callout_init(&V_expire_upcalls_ch, 1);
callout_init(&V_bw_upcalls_ch, 1);
callout_init(&V_bw_meter_ch, 1);
@ -2815,6 +2826,9 @@ static void
vnet_mroute_uninit(const void *unused __unused)
{
free(V_bw_upcalls, M_MRTABLE);
free(V_bw_meter_timers, M_MRTABLE);
free(V_viftable, M_MRTABLE);
free(V_nexpire, M_MRTABLE);
V_nexpire = NULL;
}