Module Name: src
Committed By: pooka
Date: Mon Nov 11 23:06:40 UTC 2013
Modified Files:
src/sys/rump/librump/rumpkern: intr.c
Log Message:
Defer softint thread creation to first softint_establish() for that level.
Speeds up rump kernel bootstrap and saves memory -- very rarely are all
softint levels in a rump kernel used.
To generate a diff of this commit:
cvs rdiff -u -r1.40 -r1.41 src/sys/rump/librump/rumpkern/intr.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/librump/rumpkern/intr.c
diff -u src/sys/rump/librump/rumpkern/intr.c:1.40 src/sys/rump/librump/rumpkern/intr.c:1.41
--- src/sys/rump/librump/rumpkern/intr.c:1.40 Thu May 2 21:45:28 2013
+++ src/sys/rump/librump/rumpkern/intr.c Mon Nov 11 23:06:40 2013
@@ -1,4 +1,4 @@
-/* $NetBSD: intr.c,v 1.40 2013/05/02 21:45:28 pooka Exp $ */
+/* $NetBSD: intr.c,v 1.41 2013/11/11 23:06:40 pooka Exp $ */
/*
* Copyright (c) 2008-2010 Antti Kantee. All Rights Reserved.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: intr.c,v 1.40 2013/05/02 21:45:28 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: intr.c,v 1.41 2013/11/11 23:06:40 pooka Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -188,11 +188,52 @@ sithread(void *arg)
panic("sithread unreachable");
}
+static kmutex_t sithr_emtx;
+static unsigned int sithr_est;
+static int sithr_canest;
+
+/*
+ * Create softint handler threads when the softint for each respective
+ * level is established for the first time. Most rump kernels don't
+ * need at least half of the softint levels, so on-demand saves bootstrap
+ * time and memory resources. Note, though, that this routine may be
+ * called before it's possible to call kthread_create(). Creation of
+ * those softints (SOFTINT_CLOCK, as of writing this) will be deferred
+ * to until softint_init() is called for the main CPU.
+ */
+static void
+sithread_establish(int level)
+{
+ int docreate, rv;
+ int lvlbit = 1<<level;
+ int i;
+
+ KASSERT((level & ~SOFTINT_LVLMASK) == 0);
+ if (__predict_true(sithr_est & lvlbit))
+ return;
+
+ mutex_enter(&sithr_emtx);
+ docreate = (sithr_est & lvlbit) == 0 && sithr_canest;
+ sithr_est |= lvlbit;
+ mutex_exit(&sithr_emtx);
+
+ if (docreate) {
+ for (i = 0; i < ncpu_final; i++) {
+ if ((rv = kthread_create(PRI_NONE,
+ KTHREAD_MPSAFE | KTHREAD_INTR,
+ cpu_lookup(i), sithread, (void *)(uintptr_t)level,
+ NULL, "rsi%d/%d", i, level)) != 0)
+ panic("softint thread create failed: %d", rv);
+ }
+ }
+}
+
void
rump_intr_init(int numcpu)
{
cv_init(&lbolt, "oh kath ra");
+ mutex_init(&sithr_emtx, MUTEX_DEFAULT, IPL_NONE);
ncpu_final = numcpu;
}
@@ -206,10 +247,23 @@ softint_init(struct cpu_info *ci)
if (!rump_threads)
return;
- /* XXX */
+ /* overloaded global init ... */
if (ci->ci_index == 0) {
+ int sithr_swap;
+
rumptc.tc_frequency = hz;
tc_init(&rumptc);
+
+ /* create deferred softint threads */
+ mutex_enter(&sithr_emtx);
+ sithr_swap = sithr_est;
+ sithr_est = 0;
+ sithr_canest = 1;
+ mutex_exit(&sithr_emtx);
+ for (i = 0; i < SOFTINT_COUNT; i++) {
+ if (sithr_swap & (1<<i))
+ sithread_establish(i);
+ }
}
slev = kmem_alloc(sizeof(struct softint_lev) * SOFTINT_COUNT, KM_SLEEP);
@@ -219,19 +273,9 @@ softint_init(struct cpu_info *ci)
}
cd->cpu_softcpu = slev;
- /* softint might run on different physical CPU */
- membar_sync();
-
- for (i = 0; i < SOFTINT_COUNT; i++) {
- rv = kthread_create(PRI_NONE,
- KTHREAD_MPSAFE | KTHREAD_INTR, ci,
- sithread, (void *)(uintptr_t)i,
- NULL, "rsi%d/%d", ci->ci_index, i);
- }
-
- rv = kthread_create(PRI_NONE, KTHREAD_MPSAFE,
- ci, doclock, NULL, NULL, "rumpclk%d", ci->ci_index);
- if (rv)
+ /* well, not really a "soft" interrupt ... */
+ if ((rv = kthread_create(PRI_NONE, KTHREAD_MPSAFE,
+ ci, doclock, NULL, NULL, "rumpclk%d", ci->ci_index)) != 0)
panic("clock thread creation failed: %d", rv);
}
@@ -240,13 +284,14 @@ softint_establish(u_int flags, void (*fu
{
struct softint *si;
struct softint_percpu *sip;
+ int level = flags & SOFTINT_LVLMASK;
int i;
si = malloc(sizeof(*si), M_TEMP, M_WAITOK);
si->si_func = func;
si->si_arg = arg;
si->si_flags = flags & SOFTINT_MPSAFE ? SI_MPSAFE : 0;
- si->si_level = flags & SOFTINT_LVLMASK;
+ si->si_level = level;
KASSERT(si->si_level < SOFTINT_COUNT);
si->si_entry = malloc(sizeof(*si->si_entry) * ncpu_final,
M_TEMP, M_WAITOK | M_ZERO);
@@ -254,6 +299,7 @@ softint_establish(u_int flags, void (*fu
sip = &si->si_entry[i];
sip->sip_parent = si;
}
+ sithread_establish(level);
return si;
}
