[src/trunk]: src Remove cpu_queue (and thus eleminate another use of CIRCLEQ)...

[rmind <rmind%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9777560a971e
branches:  trunk
changeset: 791599:9777560a971e
user:      rmind <rmind%NetBSD.org@localhost>
date:      Sun Nov 24 21:58:38 2013 +0000

description:
Remove cpu_queue (and thus eleminate another use of CIRCLEQ) by replacing
its uses with cpu_infos array.  Extra testing by christos@.

diffstat:

 sys/ddb/db_cpu.c        |  32 +++++++++++++++++-------------
 sys/kern/kern_cpu.c     |  17 ++++++---------
 sys/kern/kern_runq.c    |  21 +++++++++++--------
 sys/sys/cpu.h           |   4 +-
 usr.bin/vmstat/vmstat.c |  51 ++++++++++++++++++++++++------------------------
 5 files changed, 65 insertions(+), 60 deletions(-)

diffs (truncated from 308 to 300 lines):

diff -r 30378332fc92 -r 9777560a971e sys/ddb/db_cpu.c
--- a/sys/ddb/db_cpu.c  Sun Nov 24 19:49:22 2013 +0000
+++ b/sys/ddb/db_cpu.c  Sun Nov 24 21:58:38 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: db_cpu.c,v 1.4 2011/02/20 10:24:45 hannken Exp $       */
+/*     $NetBSD: db_cpu.c,v 1.5 2013/11/24 21:58:38 rmind Exp $ */
 
 /*-
  * Copyright (c) 2009 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_cpu.c,v 1.4 2011/02/20 10:24:45 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_cpu.c,v 1.5 2013/11/24 21:58:38 rmind Exp $");
 
 #ifndef _KERNEL
 #include <stdbool.h>
@@ -42,26 +42,30 @@
 
 #include <ddb/ddb.h>
 
-static struct cpu_info *head;
-static void *head_addr;
+static struct cpu_info **cpu_info_addr;
+
+static struct cpu_info *
+db_cpu_index(u_int idx)
+{
+       db_addr_t slot_addr = (db_addr_t)(cpu_info_addr + idx);
+       struct cpu_info *ci;
+
+       db_read_bytes(slot_addr, sizeof(ci), (char *)&ci);
+       return ci;
+}
 
 struct cpu_info *
 db_cpu_first(void)
 {
-
-       head = db_read_ptr("cpu_queue");
-       (void) db_value_of_name("cpu_queue", (db_expr_t *)&head_addr);
-       return head;
+       db_value_of_name("cpu_infos", (db_expr_t *)&cpu_info_addr);
+       return db_cpu_index(0);
 }
 
 struct cpu_info *
 db_cpu_next(struct cpu_info *ci)
 {
+       u_int idx;
 
-       db_read_bytes((db_addr_t)&ci->ci_data.cpu_qchain.cqe_next,
-           sizeof(ci), (char *)&ci);
-       if (ci == head_addr) {
-               ci = NULL;
-       }
-       return ci;
+       db_read_bytes((db_addr_t)&ci->ci_index, sizeof(idx), (char *)&idx);
+       return db_cpu_index(idx + 1);
 }
diff -r 30378332fc92 -r 9777560a971e sys/kern/kern_cpu.c
--- a/sys/kern/kern_cpu.c       Sun Nov 24 19:49:22 2013 +0000
+++ b/sys/kern/kern_cpu.c       Sun Nov 24 21:58:38 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_cpu.c,v 1.60 2013/08/22 19:50:55 drochner Exp $   */
+/*     $NetBSD: kern_cpu.c,v 1.61 2013/11/24 21:58:38 rmind Exp $      */
 
 /*-
  * Copyright (c) 2007, 2008, 2009, 2010, 2012 The NetBSD Foundation, Inc.
@@ -56,7 +56,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_cpu.c,v 1.60 2013/08/22 19:50:55 drochner Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_cpu.c,v 1.61 2013/11/24 21:58:38 rmind Exp $");
 
 #include "opt_cpu_ucode.h"
 #include "opt_compat_netbsd.h"
@@ -112,15 +112,13 @@
 int            ncpuonline              __read_mostly;
 bool           mp_online               __read_mostly;
 
+/* An array of CPUs.  There are ncpu entries. */
+struct cpu_info **cpu_infos            __read_mostly;
+
 /* Note: set on mi_cpu_attach() and idle_loop(). */
 kcpuset_t *    kcpuset_attached        __read_mostly   = NULL;
 kcpuset_t *    kcpuset_running         __read_mostly   = NULL;
 
-struct cpuqueue        cpu_queue               __cacheline_aligned
-    = CIRCLEQ_HEAD_INITIALIZER(cpu_queue);
-
-static struct cpu_info **cpu_infos     __read_mostly;
-
 /*
  * mi_cpu_init: early initialisation of MI CPU related structures.
  *
@@ -153,7 +151,6 @@
        kcpuset_create(&ci->ci_data.cpu_kcpuset, true);
        kcpuset_set(ci->ci_data.cpu_kcpuset, cpu_index(ci));
 
-       CIRCLEQ_INSERT_TAIL(&cpu_queue, ci, ci_data.cpu_qchain);
        TAILQ_INIT(&ci->ci_data.cpu_ld_locks);
        __cpu_simple_lock_init(&ci->ci_data.cpu_ld_lock);
 
@@ -162,8 +159,8 @@
            cpu_index(ci));
 
        if (__predict_false(cpu_infos == NULL)) {
-               cpu_infos =
-                   kmem_zalloc(sizeof(cpu_infos[0]) * maxcpus, KM_SLEEP);
+               size_t nslots = maxcpus * sizeof(struct cpu_info *) + 1;
+               cpu_infos = kmem_zalloc(nslots, KM_SLEEP);
        }
        cpu_infos[cpu_index(ci)] = ci;
 
diff -r 30378332fc92 -r 9777560a971e sys/kern/kern_runq.c
--- a/sys/kern/kern_runq.c      Sun Nov 24 19:49:22 2013 +0000
+++ b/sys/kern/kern_runq.c      Sun Nov 24 21:58:38 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_runq.c,v 1.40 2013/10/19 19:22:16 christos Exp $  */
+/*     $NetBSD: kern_runq.c,v 1.41 2013/11/24 21:58:38 rmind Exp $     */
 
 /*
  * Copyright (c) 2007, 2008 Mindaugas Rasiukevicius <rmind at NetBSD org>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_runq.c,v 1.40 2013/10/19 19:22:16 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_runq.c,v 1.41 2013/11/24 21:58:38 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -365,7 +365,7 @@
 struct cpu_info *
 sched_takecpu(struct lwp *l)
 {
-       struct cpu_info *ci, *tci, *first, *next;
+       struct cpu_info *ci, *tci, *pivot, *next;
        struct schedstate_percpu *spc;
        runqueue_t *ci_rq, *ici_rq;
        pri_t eprio, lpri, pri;
@@ -411,15 +411,18 @@
         * Look for the CPU with the lowest priority thread.  In case of
         * equal priority, choose the CPU with the fewest of threads.
         */
-       first = l->l_cpu;
-       ci = first;
-       tci = first;
+       pivot = l->l_cpu;
+       ci = pivot;
+       tci = pivot;
        lpri = PRI_COUNT;
        do {
-               next = CIRCLEQ_LOOP_NEXT(&cpu_queue, ci, ci_data.cpu_qchain);
+               if ((next = cpu_lookup(cpu_index(ci) + 1)) == NULL) {
+                       /* Reached the end, start from the beginning. */
+                       next = cpu_lookup(0);
+               }
                spc = &ci->ci_schedstate;
                ici_rq = spc->spc_sched_info;
-               pri = max(spc->spc_curpriority, spc->spc_maxpriority);
+               pri = MAX(spc->spc_curpriority, spc->spc_maxpriority);
                if (pri > lpri)
                        continue;
 
@@ -432,7 +435,7 @@
                lpri = pri;
                tci = ci;
                ci_rq = ici_rq;
-       } while (ci = next, ci != first);
+       } while (ci = next, ci != pivot);
 
        ci_rq = tci->ci_schedstate.spc_sched_info;
        ci_rq->r_ev_push.ev_count++;
diff -r 30378332fc92 -r 9777560a971e sys/sys/cpu.h
--- a/sys/sys/cpu.h     Sun Nov 24 19:49:22 2013 +0000
+++ b/sys/sys/cpu.h     Sun Nov 24 21:58:38 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu.h,v 1.37 2012/10/17 20:19:55 drochner Exp $        */
+/*     $NetBSD: cpu.h,v 1.38 2013/11/24 21:58:38 rmind Exp $   */
 
 /*-
  * Copyright (c) 2007 YAMAMOTO Takashi,
@@ -96,7 +96,7 @@
 #ifdef _KERNEL
 extern kmutex_t cpu_lock;
 extern u_int maxcpus;
-extern struct cpuqueue cpu_queue;
+extern struct cpu_info **cpu_infos;
 extern kcpuset_t *kcpuset_attached;
 extern kcpuset_t *kcpuset_running;
 
diff -r 30378332fc92 -r 9777560a971e usr.bin/vmstat/vmstat.c
--- a/usr.bin/vmstat/vmstat.c   Sun Nov 24 19:49:22 2013 +0000
+++ b/usr.bin/vmstat/vmstat.c   Sun Nov 24 21:58:38 2013 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: vmstat.c,v 1.189 2013/11/10 05:16:10 mrg Exp $ */
+/* $NetBSD: vmstat.c,v 1.190 2013/11/24 21:58:38 rmind Exp $ */
 
 /*-
  * Copyright (c) 1998, 2000, 2001, 2007 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
 #if 0
 static char sccsid[] = "@(#)vmstat.c   8.2 (Berkeley) 3/1/95";
 #else
-__RCSID("$NetBSD: vmstat.c,v 1.189 2013/11/10 05:16:10 mrg Exp $");
+__RCSID("$NetBSD: vmstat.c,v 1.190 2013/11/24 21:58:38 rmind Exp $");
 #endif
 #endif /* not lint */
 
@@ -139,15 +139,12 @@
 struct cpu_info {
        struct cpu_data ci_data;
 };
-CIRCLEQ_HEAD(cpuqueue, cpu_info);
-struct  cpuqueue cpu_queue;
-
 #else
+# include <sys/cpu.h>
+#endif
 
-# include <sys/cpu.h>
-struct  cpuqueue cpu_queue;
+struct cpu_info **cpu_infos;
 
-#endif
 /*
  * General namelist
  */
@@ -171,8 +168,8 @@
        { .n_name = "_time_second" },
 #define X_TIME         8
        { .n_name = "_time" },
-#define X_CPU_QUEUE    9
-       { .n_name = "_cpu_queue" },
+#define X_CPU_INFOS    9
+       { .n_name = "_cpu_infos" },
 #define        X_NL_SIZE       10
        { .n_name = NULL },
 };
@@ -733,7 +730,7 @@
        if (!hz)
                kread(namelist, X_HZ, &hz, sizeof(hz));
 
-       kread(namelist, X_CPU_QUEUE, &cpu_queue, sizeof(cpu_queue));
+       kread(namelist, X_CPU_INFOS, &cpu_infos, sizeof(cpu_infos));
 
        for (hdrcnt = 1;;) {
                if (!--hdrcnt)
@@ -906,8 +903,9 @@
        (void)printf("%9u swap pages in use\n", uvmexp.swpginuse);
        (void)printf("%9u swap allocations\n", uvmexp.nswget);
 
-       kread(namelist, X_CPU_QUEUE, &cpu_queue, sizeof(cpu_queue));
+       kread(namelist, X_CPU_INFOS, &cpu_infos, sizeof(cpu_infos));
        cpucounters(&cc);
+
        (void)printf("%9" PRIu64 " total faults taken\n", cc.nfault);
        (void)printf("%9" PRIu64 " traps\n", cc.ntrap);
        (void)printf("%9" PRIu64 " device interrupts\n", cc.nintr);
@@ -1028,28 +1026,31 @@
 void
 cpucounters(struct cpu_counter *cc)
 {
-       struct cpu_info *ci, *first = NULL;
-       (void)memset(cc, 0, sizeof(*cc));
-       CIRCLEQ_FOREACH(ci, &cpu_queue, ci_data.cpu_qchain) {
-               struct cpu_info tci;
+       struct cpu_info **slot = cpu_infos;
+
+       memset(cc, 0, sizeof(*cc));
+
+       for (;;) {
+               struct cpu_info tci, *ci = NULL;
+
+               deref_kptr(slot++, &ci, sizeof(ci), "CPU array trashed");
+               if (!ci) {
+                       break;
+               }
+
                if ((size_t)kvm_read(kd, (u_long)ci, &tci, sizeof(tci))
                    != sizeof(tci)) {
-                   warnx("Can't read cpu info from %p (%s)",
-                       ci, kvm_geterr(kd));
-                   (void)memset(cc, 0, sizeof(*cc));
-                   return;
+                       warnx("Can't read cpu info from %p (%s)",
+                           ci, kvm_geterr(kd));
+                       memset(cc, 0, sizeof(*cc));
+                       return;
                }
-               if (first == NULL)
-                       first = tci.ci_data.cpu_qchain.cqe_prev;
                cc->nintr += tci.ci_data.cpu_nintr;
                cc->nsyscall += tci.ci_data.cpu_nsyscall;
                cc->nswtch = tci.ci_data.cpu_nswtch;
                cc->nfault = tci.ci_data.cpu_nfault;