From: Robin Murphy <robin.murphy@arm.com>
To: hch@lst.de
Cc: m.szyprowski@samsung.com, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, cai@gmx.us, salil.mehta@huawei.com,
john.garry@huawei.com
Subject: [PATCH 2/4] dma-debug: Refactor dma_debug_entry allocation
Date: Mon, 3 Dec 2018 17:28:07 +0000 [thread overview]
Message-ID: <a827949d4fde7f8eca805e3b09c2eb7fb16d8bec.1543856576.git.robin.murphy@arm.com> (raw)
In-Reply-To: <cover.1543856576.git.robin.murphy@arm.com>
Make prealloc_memory() a little more general and robust so that it
serves for runtime reallocations too. The first thing we can do with
that is clean up dma_debug_resize_entries() quite a bit.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
kernel/dma/debug.c | 95 +++++++++++++++++++---------------------------
1 file changed, 40 insertions(+), 55 deletions(-)
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 91b84140e4a5..de5db800dbfc 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -645,6 +645,39 @@ static void add_dma_entry(struct dma_debug_entry *entry)
*/
}
+static int prealloc_memory(u32 num_entries)
+{
+ struct dma_debug_entry *entry, *next_entry;
+ unsigned long flags;
+ LIST_HEAD(tmp);
+ int i;
+
+ for (i = 0; i < num_entries; ++i) {
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ goto out_err;
+
+ list_add_tail(&entry->list, &tmp);
+ }
+
+ spin_lock_irqsave(&free_entries_lock, flags);
+ list_splice(&tmp, &free_entries);
+ num_free_entries += num_entries;
+ nr_total_entries += num_entries;
+ spin_unlock_irqrestore(&free_entries_lock, flags);
+
+ return 0;
+
+out_err:
+
+ list_for_each_entry_safe(entry, next_entry, &tmp, list) {
+ list_del(&entry->list);
+ kfree(entry);
+ }
+
+ return -ENOMEM;
+}
+
static struct dma_debug_entry *__dma_entry_alloc(void)
{
struct dma_debug_entry *entry;
@@ -714,44 +747,25 @@ int dma_debug_resize_entries(u32 num_entries)
int i, delta, ret = 0;
unsigned long flags;
struct dma_debug_entry *entry;
- LIST_HEAD(tmp);
-
- spin_lock_irqsave(&free_entries_lock, flags);
if (nr_total_entries < num_entries) {
delta = num_entries - nr_total_entries;
- spin_unlock_irqrestore(&free_entries_lock, flags);
-
- for (i = 0; i < delta; i++) {
- entry = kzalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry)
- break;
-
- list_add_tail(&entry->list, &tmp);
- }
-
- spin_lock_irqsave(&free_entries_lock, flags);
-
- list_splice(&tmp, &free_entries);
- nr_total_entries += i;
- num_free_entries += i;
+ ret = prealloc_memory(delta);
} else {
delta = nr_total_entries - num_entries;
+ spin_lock_irqsave(&free_entries_lock, flags);
for (i = 0; i < delta && !list_empty(&free_entries); i++) {
entry = __dma_entry_alloc();
kfree(entry);
}
+ spin_unlock_irqrestore(&free_entries_lock, flags);
nr_total_entries -= i;
+ if (nr_total_entries != num_entries)
+ ret = -EBUSY;
}
-
- if (nr_total_entries != num_entries)
- ret = 1;
-
- spin_unlock_irqrestore(&free_entries_lock, flags);
-
return ret;
}
@@ -763,36 +777,6 @@ int dma_debug_resize_entries(u32 num_entries)
* 2. Preallocate a given number of dma_debug_entry structs
*/
-static int prealloc_memory(u32 num_entries)
-{
- struct dma_debug_entry *entry, *next_entry;
- int i;
-
- for (i = 0; i < num_entries; ++i) {
- entry = kzalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry)
- goto out_err;
-
- list_add_tail(&entry->list, &free_entries);
- }
-
- num_free_entries = num_entries;
- min_free_entries = num_entries;
-
- pr_info("preallocated %d debug entries\n", num_entries);
-
- return 0;
-
-out_err:
-
- list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
- list_del(&entry->list);
- kfree(entry);
- }
-
- return -ENOMEM;
-}
-
static ssize_t filter_read(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
@@ -1038,7 +1022,8 @@ static int dma_debug_init(void)
return 0;
}
- nr_total_entries = num_free_entries;
+ min_free_entries = num_free_entries;
+ pr_info("preallocated %d debug entries\n", nr_total_entries);
dma_debug_initialized = true;
--
2.19.1.dirty
next prev parent reply other threads:[~2018-12-03 17:28 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 17:28 [PATCH 0/4] dma-debug: implement dynamic entry allocation Robin Murphy
2018-12-03 17:28 ` [PATCH 1/4] dma-debug: Use pr_fmt() Robin Murphy
2018-12-04 14:26 ` Christoph Hellwig
2018-12-04 17:35 ` Joe Perches
2018-12-03 17:28 ` Robin Murphy [this message]
2018-12-04 14:27 ` [PATCH 2/4] dma-debug: Refactor dma_debug_entry allocation Christoph Hellwig
2018-12-04 16:09 ` Robin Murphy
2018-12-03 17:28 ` [PATCH 3/4] dma-debug: Dynamically expand the dma_debug_entry pool Robin Murphy
2018-12-03 18:23 ` John Garry
2018-12-04 13:11 ` Robin Murphy
2018-12-04 14:17 ` Christoph Hellwig
2018-12-04 16:06 ` Robin Murphy
2018-12-04 16:30 ` John Garry
2018-12-04 17:19 ` Robin Murphy
2018-12-04 17:38 ` John Garry
2018-12-04 14:29 ` Christoph Hellwig
2018-12-04 16:32 ` Robin Murphy
2018-12-03 17:28 ` [RFC 4/4] dma-debug: Make leak-like behaviour apparent Robin Murphy
2018-12-04 14:31 ` Christoph Hellwig
2018-12-03 17:34 ` [PATCH 0/4] dma-debug: implement dynamic entry allocation Christoph Hellwig
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