Author: rwatson
Date: Fri Jun 26 00:19:25 2009
New Revision: 195019
URL: http://svn.freebsd.org/changeset/base/195019
Log:
Convert netisr to use dynamic per-CPU storage (DPCPU) instead of sizing
arrays to [MAXCPU], offering moderate memory savings. In some places,
this requires using CPU_ABSENT() to handle less common platforms with
sparse CPU IDs. In several places, assert that the selected CPUID for
work placement or statistics is not CPU_ABSENT() to be on the safe side.
Discussed with: bz, jeff
Modified:
head/sys/net/netisr.c
Modified: head/sys/net/netisr.c
==============================================================================
--- head/sys/net/netisr.c Fri Jun 26 00:15:26 2009 (r195018)
+++ head/sys/net/netisr.c Fri Jun 26 00:19:25 2009 (r195019)
@@ -70,6 +70,7 @@ __FBSDID("$FreeBSD$");
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
+#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/rmlock.h>
#include <sys/sched.h>
@@ -258,14 +259,14 @@ struct netisr_workstream {
} __aligned(CACHE_LINE_SIZE);
/*
- * Per-CPU workstream data, indexed by CPU ID.
+ * Per-CPU workstream data.
*/
-static struct netisr_workstream nws[MAXCPU];
+DPCPU_DEFINE(struct netisr_workstream, nws);
/*
* Map contiguous values between 0 and nws_count into CPU IDs appropriate for
- * indexing the nws[] array. This allows constructions of the form
- * nws[nws_array(arbitraryvalue % nws_count)].
+ * accessing workstreams. This allows constructions of the form
+ * DPCPU_ID_GET(nws_array[arbitraryvalue % nws_count], nws).
*/
static u_int nws_array[MAXCPU];
@@ -393,7 +394,9 @@ netisr_register(const struct netisr_hand
np[proto].np_qlimit = nhp->nh_qlimit;
np[proto].np_policy = nhp->nh_policy;
for (i = 0; i < MAXCPU; i++) {
- npwp = &nws[i].nws_work[proto];
+ if (CPU_ABSENT(i))
+ continue;
+ npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
bzero(npwp, sizeof(*npwp));
npwp->nw_qlimit = np[proto].np_qlimit;
}
@@ -425,7 +428,9 @@ netisr_clearqdrops(const struct netisr_h
name));
for (i = 0; i < MAXCPU; i++) {
- npwp = &nws[i].nws_work[proto];
+ if (CPU_ABSENT(i))
+ continue;
+ npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
npwp->nw_qdrops = 0;
}
NETISR_WUNLOCK();
@@ -458,7 +463,9 @@ netisr_getqdrops(const struct netisr_han
name));
for (i = 0; i < MAXCPU; i++) {
- npwp = &nws[i].nws_work[proto];
+ if (CPU_ABSENT(i))
+ continue;
+ npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
*qdropp += npwp->nw_qdrops;
}
NETISR_RUNLOCK(&tracker);
@@ -522,7 +529,9 @@ netisr_setqlimit(const struct netisr_han
np[proto].np_qlimit = qlimit;
for (i = 0; i < MAXCPU; i++) {
- npwp = &nws[i].nws_work[proto];
+ if (CPU_ABSENT(i))
+ continue;
+ npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
npwp->nw_qlimit = qlimit;
}
NETISR_WUNLOCK();
@@ -586,7 +595,9 @@ netisr_unregister(const struct netisr_ha
np[proto].np_qlimit = 0;
np[proto].np_policy = 0;
for (i = 0; i < MAXCPU; i++) {
- npwp = &nws[i].nws_work[proto];
+ if (CPU_ABSENT(i))
+ continue;
+ npwp = &(DPCPU_ID_PTR(i, nws))->nws_work[proto];
netisr_drain_proto(npwp);
bzero(npwp, sizeof(*npwp));
}
@@ -809,10 +820,11 @@ netisr_queue_internal(u_int proto, struc
#endif
KASSERT(cpuid < MAXCPU, ("%s: cpuid too big (%u, %u)", __func__,
cpuid, MAXCPU));
+ KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
dosignal = 0;
error = 0;
- nwsp = &nws[cpuid];
+ nwsp = DPCPU_ID_PTR(cpuid, nws);
npwp = &nwsp->nws_work[proto];
NWS_LOCK(nwsp);
error = netisr_queue_workstream(nwsp, proto, npwp, m, &dosignal);
@@ -841,9 +853,11 @@ netisr_queue_src(u_int proto, uintptr_t
("%s: invalid proto %u", __func__, proto));
m = netisr_select_cpuid(&np[proto], source, m, &cpuid);
- if (m != NULL)
+ if (m != NULL) {
+ KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__,
+ cpuid));
error = netisr_queue_internal(proto, m, cpuid);
- else
+ } else
error = ENOBUFS;
#ifdef NETISR_LOCKING
NETISR_RUNLOCK(&tracker);
@@ -895,7 +909,7 @@ netisr_dispatch_src(u_int proto, uintptr
* to always being forced to directly dispatch.
*/
if (netisr_direct_force) {
- nwsp = &nws[curcpu];
+ nwsp = DPCPU_PTR(nws);
npwp = &nwsp->nws_work[proto];
npwp->nw_dispatched++;
npwp->nw_handled++;
@@ -914,10 +928,11 @@ netisr_dispatch_src(u_int proto, uintptr
error = ENOBUFS;
goto out_unlock;
}
+ KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
sched_pin();
if (cpuid != curcpu)
goto queue_fallback;
- nwsp = &nws[cpuid];
+ nwsp = DPCPU_PTR(nws);
npwp = &nwsp->nws_work[proto];
/*-
@@ -931,7 +946,7 @@ netisr_dispatch_src(u_int proto, uintptr
if (nwsp->nws_flags & (NWS_RUNNING | NWS_DISPATCHING | NWS_SCHEDULED)) {
error = netisr_queue_workstream(nwsp, proto, npwp, m,
&dosignal);
- NWS_UNLOCK(nws);
+ NWS_UNLOCK(nwsp);
if (dosignal)
NWS_SIGNAL(nwsp);
goto out_unpin;
@@ -999,7 +1014,7 @@ netisr_sched_poll(void)
{
struct netisr_workstream *nwsp;
- nwsp = &nws[nws_array[0]];
+ nwsp = DPCPU_ID_PTR(nws_array[0], nws);
NWS_SIGNAL(nwsp);
}
#endif
@@ -1011,7 +1026,9 @@ netisr_start_swi(u_int cpuid, struct pcp
struct netisr_workstream *nwsp;
int error;
- nwsp = &nws[cpuid];
+ KASSERT(!CPU_ABSENT(cpuid), ("%s: CPU %u absent", __func__, cpuid));
+
+ nwsp = DPCPU_ID_PTR(cpuid, nws);
mtx_init(&nwsp->nws_mtx, "netisr_mtx", NULL, MTX_DEF);
nwsp->nws_cpu = cpuid;
snprintf(swiname, sizeof(swiname), "netisr %u", cpuid);
@@ -1107,12 +1124,14 @@ DB_SHOW_COMMAND(netisr, db_show_netisr)
struct netisr_workstream *nwsp;
struct netisr_work *nwp;
int first, proto;
- u_int cpu;
+ u_int cpuid;
db_printf("%3s %6s %5s %5s %5s %8s %8s %8s %8s\n", "CPU", "Proto",
"Len", "WMark", "Max", "Disp", "HDisp", "Drop", "Queue");
- for (cpu = 0; cpu < MAXCPU; cpu++) {
- nwsp = &nws[cpu];
+ for (cpuid = 0; cpuid < MAXCPU; cpuid++) {
+ if (CPU_ABSENT(cpuid))
+ continue;
+ nwsp = DPCPU_ID_PTR(cpuid, nws);
if (nwsp->nws_intr_event == NULL)
continue;
first = 1;
@@ -1121,7 +1140,7 @@ DB_SHOW_COMMAND(netisr, db_show_netisr)
continue;
nwp = &nwsp->nws_work[proto];
if (first) {
- db_printf("%3d ", cpu);
+ db_printf("%3d ", cpuid);
first = 0;
} else
db_printf("%3s ", "");
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