[src/trunk]: src/sys/kern entropy(9): Count dropped or truncated interrupt sa...

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

details:   https://anonhg.NetBSD.org/src/rev/5bc5e1177db6
branches:  trunk
changeset: 363957:5bc5e1177db6
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Fri Mar 18 23:35:28 2022 +0000

description:
entropy(9): Count dropped or truncated interrupt samples.

diffstat:

 sys/kern/kern_entropy.c |  37 +++++++++++++++++++++++++------------
 1 files changed, 25 insertions(+), 12 deletions(-)

diffs (102 lines):

diff -r b5046c26e7b6 -r 5bc5e1177db6 sys/kern/kern_entropy.c
--- a/sys/kern/kern_entropy.c   Fri Mar 18 23:35:19 2022 +0000
+++ b/sys/kern/kern_entropy.c   Fri Mar 18 23:35:28 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_entropy.c,v 1.39 2022/03/18 23:35:19 riastradh Exp $      */
+/*     $NetBSD: kern_entropy.c,v 1.40 2022/03/18 23:35:28 riastradh Exp $      */
 
 /*-
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -75,7 +75,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_entropy.c,v 1.39 2022/03/18 23:35:19 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_entropy.c,v 1.40 2022/03/18 23:35:28 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -130,7 +130,11 @@
  *     evcnt(9) assumes it stays put in memory.
  */
 struct entropy_cpu {
-       struct evcnt            *ec_softint_evcnt;
+       struct entropy_cpu_evcnt {
+               struct evcnt            softint;
+               struct evcnt            intrdrop;
+               struct evcnt            intrtrunc;
+       }                       *ec_evcnt;
        struct entpool          *ec_pool;
        unsigned                ec_pending;
        bool                    ec_locked;
@@ -466,17 +470,21 @@
 entropy_init_cpu(void *ptr, void *cookie, struct cpu_info *ci)
 {
        struct entropy_cpu *ec = ptr;
+       const char *cpuname;
 
-       ec->ec_softint_evcnt = kmem_alloc(sizeof(*ec->ec_softint_evcnt),
-           KM_SLEEP);
+       ec->ec_evcnt = kmem_alloc(sizeof(*ec->ec_evcnt), KM_SLEEP);
        ec->ec_pool = kmem_zalloc(sizeof(*ec->ec_pool), KM_SLEEP);
        ec->ec_pending = 0;
        ec->ec_locked = false;
 
        /* XXX ci_cpuname may not be initialized early enough.  */
-       evcnt_attach_dynamic(ec->ec_softint_evcnt, EVCNT_TYPE_MISC, NULL,
-           ci->ci_cpuname[0] == '\0' ? "cpu0" : ci->ci_cpuname,
-           "entropy softint");
+       cpuname = ci->ci_cpuname[0] == '\0' ? "cpu0" : ci->ci_cpuname;
+       evcnt_attach_dynamic(&ec->ec_evcnt->softint, EVCNT_TYPE_MISC, NULL,
+           cpuname, "entropy softint");
+       evcnt_attach_dynamic(&ec->ec_evcnt->intrdrop, EVCNT_TYPE_MISC, NULL,
+           cpuname, "entropy intrdrop");
+       evcnt_attach_dynamic(&ec->ec_evcnt->intrtrunc, EVCNT_TYPE_MISC, NULL,
+           cpuname, "entropy intrtrunc");
 }
 
 /*
@@ -497,10 +505,12 @@
         */
        explicit_memset(ec->ec_pool, 0, sizeof(*ec->ec_pool));
 
-       evcnt_detach(ec->ec_softint_evcnt);
+       evcnt_detach(&ec->ec_evcnt->intrtrunc);
+       evcnt_detach(&ec->ec_evcnt->intrdrop);
+       evcnt_detach(&ec->ec_evcnt->softint);
 
        kmem_free(ec->ec_pool, sizeof(*ec->ec_pool));
-       kmem_free(ec->ec_softint_evcnt, sizeof(*ec->ec_softint_evcnt));
+       kmem_free(ec->ec_evcnt, sizeof(*ec->ec_evcnt));
 }
 
 /*
@@ -872,8 +882,10 @@
         * higher-priority interrupts will drop their samples.
         */
        ec = percpu_getref(entropy_percpu);
-       if (ec->ec_locked)
+       if (ec->ec_locked) {
+               ec->ec_evcnt->intrdrop.ev_count++;
                goto out0;
+       }
        ec->ec_locked = true;
        __insn_barrier();
 
@@ -885,6 +897,7 @@
                sih = atomic_load_relaxed(&entropy_sih);
                if (__predict_true(sih != NULL))
                        softint_schedule(sih);
+               ec->ec_evcnt->intrtrunc.ev_count++;
                goto out1;
        }
        fullyused = true;
@@ -936,7 +949,7 @@
        __insn_barrier();
 
        /* Count statistics.  */
-       ec->ec_softint_evcnt->ev_count++;
+       ec->ec_evcnt->softint.ev_count++;
 
        /* Stir the pool if necessary.  */
        entpool_stir(ec->ec_pool);