dma-debug: make things less spammy under memory pressure

Limit the error msg to avoid flooding the console.  If you have a lot of
threads hitting this at once, they could have already gotten passed the
dma_debug_disabled() check before they get to the point of allocation
failure, resulting in quite a lot of this error message spamming the
log.  Use pr_err_once() to limit that.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index ac74063..2caafd1 100644 (file)
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -564,7 +564,7 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
 
        rc = active_cacheline_insert(entry);
        if (rc == -ENOMEM) {
-               pr_err("cacheline tracking ENOMEM, dma-debug disabled\n");
+               pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n");
                global_disable = true;
        } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
                err_printk(entry->dev, entry,