[src/trunk]: src/sys/dev/raidframe getiobuf() can return NULL if there are no...

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

details:   https://anonhg.NetBSD.org/src/rev/816c3e567eed
branches:  trunk
changeset: 1022502:816c3e567eed
user:      oster <oster%NetBSD.org@localhost>
date:      Fri Jul 23 00:26:19 2021 +0000

description:
getiobuf() can return NULL if there are no IO buffers available.
RAIDframe can't deal with that, so create a dedicated pool of buffers
to use for IO.  PR_WAITOK is fine here, as we pre-allocate more than
we need to guarantee IO can make progress.  Tuning of pool still to
come.

diffstat:

 sys/dev/raidframe/rf_diskqueue.c |  43 +++++++++++++++++++++++++--------------
 sys/dev/raidframe/rf_netbsd.h    |   3 +-
 2 files changed, 29 insertions(+), 17 deletions(-)

diffs (119 lines):

diff -r 664fcc53a198 -r 816c3e567eed sys/dev/raidframe/rf_diskqueue.c
--- a/sys/dev/raidframe/rf_diskqueue.c  Thu Jul 22 21:49:44 2021 +0000
+++ b/sys/dev/raidframe/rf_diskqueue.c  Fri Jul 23 00:26:19 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rf_diskqueue.c,v 1.58 2020/06/19 19:32:03 jdolecek Exp $       */
+/*     $NetBSD: rf_diskqueue.c,v 1.59 2021/07/23 00:26:19 oster Exp $  */
 /*
  * Copyright (c) 1995 Carnegie-Mellon University.
  * All rights reserved.
@@ -66,7 +66,7 @@
  ****************************************************************************/
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rf_diskqueue.c,v 1.58 2020/06/19 19:32:03 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rf_diskqueue.c,v 1.59 2021/07/23 00:26:19 oster Exp $");
 
 #include <dev/raidframe/raidframevar.h>
 
@@ -84,6 +84,8 @@
 #include "rf_fifo.h"
 #include "rf_kintf.h"
 
+#include <sys/buf.h>
+
 static void rf_ShutdownDiskQueueSystem(void *);
 
 #ifndef RF_DEBUG_DISKQUEUE
@@ -147,10 +149,15 @@
 };
 #define NUM_DISK_QUEUE_TYPES (sizeof(diskqueuesw)/sizeof(RF_DiskQueueSW_t))
 
+
 #define RF_MAX_FREE_DQD 256
 #define RF_MIN_FREE_DQD  64
 
-#include <sys/buf.h>
+/* XXX: scale these... */
+#define RF_MAX_FREE_BUFIO 256
+#define RF_MIN_FREE_BUFIO  64
+
+
 
 /* configures a single disk queue */
 
@@ -189,6 +196,7 @@
 rf_ShutdownDiskQueueSystem(void *ignored)
 {
        pool_destroy(&rf_pools.dqd);
+       pool_destroy(&rf_pools.bufio);
 }
 
 int
@@ -197,6 +205,8 @@
 
        rf_pool_init(&rf_pools.dqd, sizeof(RF_DiskQueueData_t),
                     "rf_dqd_pl", RF_MIN_FREE_DQD, RF_MAX_FREE_DQD);
+       rf_pool_init(&rf_pools.bufio, sizeof(buf_t),
+                    "rf_bufio_pl", RF_MIN_FREE_BUFIO, RF_MAX_FREE_BUFIO);
        rf_ShutdownCreate(listp, rf_ShutdownDiskQueueSystem, NULL);
 
        return (0);
@@ -367,19 +377,20 @@
 {
        RF_DiskQueueData_t *p;
 
-       p = pool_get(&rf_pools.dqd, waitflag | PR_ZERO);
-       if (p == NULL)
-               return (NULL);
+       p = pool_get(&rf_pools.dqd, PR_WAITOK | PR_ZERO);
+       KASSERT(p != NULL);
 
-       if (waitflag == PR_WAITOK) {
-               p->bp = getiobuf(NULL, true);
-       } else {
-               p->bp = getiobuf(NULL, false);
-       }
-       if (p->bp == NULL) {
-               pool_put(&rf_pools.dqd, p);
-               return (NULL);
-       }
+       /* Obtain a buffer from our own pool.  It is possible for the
+          regular getiobuf() to run out of memory and return NULL.
+          We need to guarantee that never happens, as RAIDframe
+          doesn't have a good way to recover if memory allocation
+          fails here.
+       */
+       p->bp = pool_get(&rf_pools.bufio, PR_WAITOK | PR_ZERO);
+       KASSERT(p->bp != NULL);
+       
+       buf_init(p->bp);
+               
        SET(p->bp->b_cflags, BC_BUSY);  /* mark buffer busy */
        if (mbp) {
                SET(p->bp->b_flags, mbp->b_flags & rf_b_pass);
@@ -405,6 +416,6 @@
 void
 rf_FreeDiskQueueData(RF_DiskQueueData_t *p)
 {
-       putiobuf(p->bp);
+       pool_put(&rf_pools.bufio, p->bp);
        pool_put(&rf_pools.dqd, p);
 }
diff -r 664fcc53a198 -r 816c3e567eed sys/dev/raidframe/rf_netbsd.h
--- a/sys/dev/raidframe/rf_netbsd.h     Thu Jul 22 21:49:44 2021 +0000
+++ b/sys/dev/raidframe/rf_netbsd.h     Fri Jul 23 00:26:19 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rf_netbsd.h,v 1.35 2020/06/19 19:29:39 jdolecek Exp $  */
+/*     $NetBSD: rf_netbsd.h,v 1.36 2021/07/23 00:26:19 oster Exp $     */
 
 /*-
  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
@@ -61,6 +61,7 @@
        struct pool asm_hdr;     /* Access Stripe Map Header */
        struct pool asmap;       /* Access Stripe Map */
        struct pool asmhle;      /* Access Stripe Map Header List Elements */
+       struct pool bufio;       /* Buffer IO Pool */
        struct pool callbackf;   /* Callback function descriptors */
        struct pool callbackv;   /* Callback value descriptors */
        struct pool dagh;        /* DAG headers */