Re: [PATCH] need_resched abstraction

Rusty Russell (rusty@rustcorp.com.au)
Wed, 16 Jan 2002 16:16:39 +1100


In message <Pine.LNX.4.33.0201151904120.1357-100000@penguin.transmeta.com> you
write:
>
> On Wed, 16 Jan 2002, Rusty Russell wrote:
> > ... And I prefer maybe_schedule().
>
> My tree calls them "cond_resched()" and "need_resched()" respectively.

Bastard! Then please apply (thanks to Andrew Morton):

diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/drivers/block/ll_rw_blk.c working-2.5.3-pre1-ll/drivers/block/ll_rw_blk.c
--- linux-2.5.3-pre1/drivers/block/ll_rw_blk.c Tue Jan 15 17:25:32 2002
+++ working-2.5.3-pre1-ll/drivers/block/ll_rw_blk.c Wed Jan 16 16:15:10 2002
@@ -996,6 +996,7 @@
if (++rl->count >= batch_requests &&waitqueue_active(&rl->wait))
wake_up(&rl->wait);
}
+ cond_resched();
}

/*
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/fs/buffer.c working-2.5.3-pre1-ll/fs/buffer.c
--- linux-2.5.3-pre1/fs/buffer.c Tue Jan 15 17:25:47 2002
+++ working-2.5.3-pre1-ll/fs/buffer.c Wed Jan 16 16:15:10 2002
@@ -250,12 +250,19 @@
struct buffer_head * next;
int nr;

- next = lru_list[index];
nr = nr_buffers_type[index];
+repeat:
+ next = lru_list[index];
while (next && --nr >= 0) {
struct buffer_head *bh = next;
next = bh->b_next_free;

+ if (dev == NODEV && need_resched()) {
+ spin_unlock(&lru_list_lock);
+ cond_resched();
+ spin_lock(&lru_list_lock);
+ goto repeat;
+ }
if (!buffer_locked(bh)) {
if (refile)
__refile_buffer(bh);
@@ -1180,8 +1187,10 @@
struct buffer_head * bh = __getblk(bdev, block, size);

touch_buffer(bh);
- if (buffer_uptodate(bh))
+ if (buffer_uptodate(bh)) {
+ cond_resched();
return bh;
+ }
ll_rw_block(READ, 1, &bh);
wait_on_buffer(bh);
if (buffer_uptodate(bh))
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/fs/dcache.c working-2.5.3-pre1-ll/fs/dcache.c
--- linux-2.5.3-pre1/fs/dcache.c Tue Jan 15 17:25:47 2002
+++ working-2.5.3-pre1-ll/fs/dcache.c Wed Jan 16 16:15:10 2002
@@ -84,6 +84,7 @@
iput(inode);
} else
spin_unlock(&dcache_lock);
+ cond_resched();
}

/*
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/fs/jbd/commit.c working-2.5.3-pre1-ll/fs/jbd/commit.c
--- linux-2.5.3-pre1/fs/jbd/commit.c Tue Jan 15 17:25:48 2002
+++ working-2.5.3-pre1-ll/fs/jbd/commit.c Wed Jan 16 16:15:10 2002
@@ -212,6 +212,16 @@
__journal_remove_journal_head(bh);
refile_buffer(bh);
__brelse(bh);
+ if (need_resched()) {
+ if (commit_transaction->t_sync_datalist)
+ commit_transaction->t_sync_datalist =
+ next_jh;
+ if (bufs)
+ break;
+ spin_unlock(&journal_datalist_lock);
+ cond_resched();
+ goto write_out_data;
+ }
}
}
if (bufs == ARRAY_SIZE(wbuf)) {
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/fs/proc/array.c working-2.5.3-pre1-ll/fs/proc/array.c
--- linux-2.5.3-pre1/fs/proc/array.c Wed Jan 16 10:52:29 2002
+++ working-2.5.3-pre1-ll/fs/proc/array.c Wed Jan 16 16:15:10 2002
@@ -419,6 +419,8 @@
pte_t page = *pte;
struct page *ptpage;

+ cond_resched();
+
address += PAGE_SIZE;
pte++;
if (pte_none(page))
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/fs/proc/generic.c working-2.5.3-pre1-ll/fs/proc/generic.c
--- linux-2.5.3-pre1/fs/proc/generic.c Sat Sep 8 03:53:59 2001
+++ working-2.5.3-pre1-ll/fs/proc/generic.c Wed Jan 16 16:15:10 2002
@@ -98,7 +98,9 @@
retval = n;
break;
}
-
+
+ cond_resched();
+
/* This is a hack to allow mangling of file pos independent
* of actual bytes read. Simply place the data at page,
* return the bytes, and set `start' to the desired offset
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.3-pre1/mm/filemap.c working-2.5.3-pre1-ll/mm/filemap.c
--- linux-2.5.3-pre1/mm/filemap.c Wed Jan 16 10:52:30 2002
+++ working-2.5.3-pre1-ll/mm/filemap.c Wed Jan 16 16:15:10 2002
@@ -603,6 +603,7 @@
UnlockPage(page);

page_cache_release(page);
+ cond_resched();
spin_lock(&pagecache_lock);
}
spin_unlock(&pagecache_lock);
@@ -1386,6 +1387,9 @@
offset &= ~PAGE_CACHE_MASK;

page_cache_release(page);
+
+ cond_resched();
+
if (ret == nr && desc->count)
continue;
break;
@@ -3019,6 +3023,8 @@
SetPageReferenced(page);
UnlockPage(page);
page_cache_release(page);
+
+ cond_resched();

if (status < 0)
break;

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
-
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