Re: [PATCH] drm: qxl: ratelimit pr_info message, reduce log spamming

From: Colin Ian King <redacted>

Simply mmap'ing /dev/dri/card0 repeatedly will spam the kernel
log with qxl_mmap information messages. The following example code
illustrates this:

int main(void)
{
        int fd = open("/dev/dri/card0", O_RDONLY);
        if (fd == -1)
                err(1, "open failed");

        for (;;) {
                void *m = mmap(NULL, 4096, PROT_READ,
                        MAP_SHARED, fd, 0);
                if (m != MAP_FAILED)
                        munmap(m, 4096);
        }
}

Reduce the spamming by ratelimiting the pr_info messages.

Signed-off-by: Colin Ian King <redacted>
---
 drivers/gpu/drm/qxl/qxl_ttm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/qxl/qxl_ttm.c b/drivers/gpu/drm/qxl/qxl_ttm.c
index 7ecf8a4b9fe6..6502e699f462 100644
--- a/drivers/gpu/drm/qxl/qxl_ttm.c
+++ b/drivers/gpu/drm/qxl/qxl_ttm.c

@@ -124,7 +124,7 @@ int qxl_mmap(struct file *filp, struct vm_area_struct *vma)
        int r;

        if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET)) {
-               pr_info("%s: vma->vm_pgoff (%ld) < DRM_FILE_PAGE_OFFSET\n",
+               pr_info_ratelimited("%s: vma->vm_pgoff (%ld) < DRM_FILE_PAGE_OFFSET\n",