Re: [PATCH 07/14] repair: use single prefetch queue

Christoph Hellwig
2009-11-12T10:09:38Z

On Wed, Oct 21, 2009 at 12:48:35PM -0500, Alex Elder wrote:
> The following hunk doesn't really do anything but change whitespace.
> It'd be nice if those changes (when there's a bunch like this) were
> limited to a separate no-op patch.

Agreed. There were lots of hunk like that in Barry's original patches
and I though I caught them all, but this one was left over.

Updated patch below:

--

Subject: repair: use single prefetch queue
From: Barry Naujok <bnaujok@sgi.com>

We don't need two prefetch queues as we guarantee execution in order anyway.

Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

Index: xfsprogs-dev/repair/prefetch.c
===================================================================
--- xfsprogs-dev.orig/repair/prefetch.c 2009-11-12 11:01:42.533256209 +0100
+++ xfsprogs-dev/repair/prefetch.c 2009-11-12 11:07:32.068006860 +0100
@@ -128,8 +128,9 @@ pf_queue_io(

pthread_mutex_lock(&args->lock);

+ btree_insert(args->io_queue, fsbno, bp);
+
if (fsbno > args->last_bno_read) {
- btree_insert(args->primary_io_queue, fsbno, bp);
if (B_IS_INODE(flag)) {
args->inode_bufs_queued++;
if (args->inode_bufs_queued == IO_THRESHOLD)
@@ -152,7 +153,6 @@ pf_queue_io(
#endif
ASSERT(!B_IS_INODE(flag));
XFS_BUF_SET_PRIORITY(bp, B_DIR_META_2);
- btree_insert(args->secondary_io_queue, fsbno, bp);
}

pf_start_processing(args);
@@ -405,7 +405,6 @@ pf_batch_read(
pf_which_t which,
void *buf)
{
- struct btree_root *queue;
xfs_buf_t *bplist[MAX_BUFS];
unsigned int num;
off64_t first_off, last_off, next_off;
@@ -416,19 +415,22 @@ pf_batch_read(
unsigned long max_fsbno;
char *pbuf;

- queue = (which != PF_SECONDARY) ? args->primary_io_queue
- : args->secondary_io_queue;
-
- while (btree_find(queue, 0, &fsbno) != NULL) {
- max_fsbno = fsbno + pf_max_fsbs;
+ for (;;) {
num = 0;
-
- bplist[0] = btree_lookup(queue, fsbno);
+ if (which == PF_SECONDARY) {
+ bplist[0] = btree_find(args->io_queue, 0, &fsbno);
+ max_fsbno = MIN(fsbno + pf_max_fsbs,
+ args->last_bno_read);
+ } else {
+ bplist[0] = btree_find(args->io_queue,
+ args->last_bno_read, &fsbno);
+ max_fsbno = fsbno + pf_max_fsbs;
+ }
while (bplist[num] && num < MAX_BUFS && fsbno < max_fsbno) {
if (which != PF_META_ONLY ||
!B_IS_INODE(XFS_BUF_PRIORITY(bplist[num])))
num++;
- bplist[num] = btree_lookup_next(queue, &fsbno);
+ bplist[num] = btree_lookup_next(args->io_queue, &fsbno);
}
if (!num)
return;
@@ -463,7 +465,7 @@ pf_batch_read(
}

for (i = 0; i < num; i++) {
- if (btree_delete(queue, XFS_DADDR_TO_FSB(mp,
+ if (btree_delete(args->io_queue, XFS_DADDR_TO_FSB(mp,
XFS_BUF_ADDR(bplist[i]))) == NULL)
do_error(_("prefetch corruption\n"));
}
@@ -566,7 +568,7 @@ pf_io_worker(
return NULL;

pthread_mutex_lock(&args->lock);
- while (!args->queuing_done || !btree_is_empty(args->primary_io_queue)) {
+ while (!args->queuing_done || !btree_is_empty(args->io_queue)) {
#ifdef XR_PF_TRACE
pftrace("waiting to start prefetch I/O for AG %d", args->agno);
#endif
@@ -691,8 +693,7 @@ pf_queuing_worker(
#endif
pthread_mutex_lock(&args->lock);

- ASSERT(btree_is_empty(args->primary_io_queue));
- ASSERT(btree_is_empty(args->secondary_io_queue));
+ ASSERT(btree_is_empty(args->io_queue));

args->prefetch_done = 1;
if (args->next_args)
@@ -750,8 +751,7 @@ start_inode_prefetch(

args = calloc(1, sizeof(prefetch_args_t));

- btree_init(&args->primary_io_queue);
- btree_init(&args->secondary_io_queue);
+ btree_init(&args->io_queue);
if (pthread_mutex_init(&args->lock, NULL) != 0)
do_error(_("failed to initialize prefetch mutex\n"));
if (pthread_cond_init(&args->start_reading, NULL) != 0)
@@ -830,8 +830,7 @@ cleanup_inode_prefetch(
pthread_cond_destroy(&args->start_reading);
pthread_cond_destroy(&args->start_processing);
sem_destroy(&args->ra_count);
- btree_destroy(args->primary_io_queue);
- btree_destroy(args->secondary_io_queue);
+ btree_destroy(args->io_queue);

free(args);
}
Index: xfsprogs-dev/repair/prefetch.h
===================================================================
--- xfsprogs-dev.orig/repair/prefetch.h 2009-11-12 10:53:01.098026017 +0100
+++ xfsprogs-dev/repair/prefetch.h 2009-11-12 11:07:01.807004122 +0100
@@ -13,8 +13,7 @@ typedef struct prefetch_args {
pthread_mutex_t lock;
pthread_t queuing_thread;
pthread_t io_threads[PF_THREAD_COUNT];
- struct btree_root *primary_io_queue;
- struct btree_root *secondary_io_queue;
+ struct btree_root *io_queue;
pthread_cond_t start_reading;
pthread_cond_t start_processing;
int agno;