From: Jens Axboe <jens.axboe@xxxxxxxxxx>
Subject: Re: [PATCH] add bsg queue resize
Date: Tue, 23 Jan 2007 16:23:49 +0100
> On Tue, Jan 23 2007, Jens Axboe wrote:
> > On Sat, Jan 20 2007, FUJITA Tomonori wrote:
> > > This enables bsg to resize the queue depth via
> > > SG_SET_COMMAND_Q. bsg_command structures are allocated via mempool
> > > because the previous way to use contiguous memory makes it difficult
> > > to resize the queue depth when a bsg_device has outstanding commands.
> >
> > Overall the patch looks fine. I don't think we need a mempool though,
> > and allocations could just use GFP_USER from the user invoked queuing
> > paths. Just make it GFP_USER, we can always extend the
> > bsg_alloc_command() to take a gfp_t argument as well If you get rid of
> > the mempool, then resizing is simply just adjusting bd->max_queue.
>
> Like so.
Thanks. I thought that pre-allocating bsg_command structures would be
nice. But it doesn't matter much for me.
One minor comment is that we could simplify __bsg_alloc_command
failpath a bit?
---
>From 6cebe0e87adc90ba50067f017c52a233fb9262d6 Mon Sep 17 00:00:00 2001
From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Date: Wed, 24 Jan 2007 11:08:47 +0900
Subject: [PATCH] bsg: simplify __bsg_alloc_command failpath
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
block/bsg.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/block/bsg.c b/block/bsg.c
index e97e3ec..c85d961 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -128,7 +128,8 @@ static struct bsg_command *__bsg_alloc_command(struct bsg_device *bd)
bc = kmem_cache_alloc(bsg_cmd_cachep, GFP_USER);
if (unlikely(!bc)) {
spin_lock_irq(&bd->lock);
- goto alloc_fail;
+ bd->queued_cmds--;
+ goto out;
}
memset(bc, 0, sizeof(*bc));
@@ -136,8 +137,6 @@ static struct bsg_command *__bsg_alloc_command(struct bsg_device *bd)
INIT_LIST_HEAD(&bc->list);
dprintk("%s: returning free cmd %p\n", bd->name, bc);
return bc;
-alloc_fail:
- bd->queued_cmds--;
out:
spin_unlock_irq(&bd->lock);
return bc;
--
1.4.4.3
-
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