Am 17.04.21 um 16:21 schrieb Muchun Song:
On Sat, Apr 17, 2021 at 9:44 PM Peter.Enderborg@sony.com wrote:
On 4/17/21 3:07 PM, Muchun Song wrote:
On Sat, Apr 17, 2021 at 6:41 PM Peter Enderborg peter.enderborg@sony.com wrote:
This adds a total used dma-buf memory. Details can be found in debugfs, however it is not for everyone and not always available. dma-buf are indirect allocated by userspace. So with this value we can monitor and detect userspace applications that have problems.
Signed-off-by: Peter Enderborg peter.enderborg@sony.com
drivers/dma-buf/dma-buf.c | 13 +++++++++++++ fs/proc/meminfo.c | 5 ++++- include/linux/dma-buf.h | 1 + 3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index f264b70c383e..197e5c45dd26 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -37,6 +37,7 @@ struct dma_buf_list { };
static struct dma_buf_list db_list; +static atomic_long_t dma_buf_global_allocated;
static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen) { @@ -79,6 +80,7 @@ static void dma_buf_release(struct dentry *dentry) if (dmabuf->resv == (struct dma_resv *)&dmabuf[1]) dma_resv_fini(dmabuf->resv);
atomic_long_sub(dmabuf->size, &dma_buf_global_allocated); module_put(dmabuf->owner); kfree(dmabuf->name); kfree(dmabuf);@@ -586,6 +588,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) mutex_lock(&db_list.lock); list_add(&dmabuf->list_node, &db_list.head); mutex_unlock(&db_list.lock);
atomic_long_add(dmabuf->size, &dma_buf_global_allocated); return dmabuf;@@ -1346,6 +1349,16 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) } EXPORT_SYMBOL_GPL(dma_buf_vunmap);
+/**
- dma_buf_allocated_pages - Return the used nr of pages
- allocated for dma-buf
- */
+long dma_buf_allocated_pages(void) +{
return atomic_long_read(&dma_buf_global_allocated) >> PAGE_SHIFT;+} +EXPORT_SYMBOL_GPL(dma_buf_allocated_pages);
dma_buf_allocated_pages is only called from fs/proc/meminfo.c. I am confused why it should be exported. If it won't be called from the driver module, we should not export it.
Ah. I thought you did not want the GPL restriction. I don't have real opinion about it. It's written to be following the rest of the module. It is not needed for the usage of dma-buf in kernel module. But I don't see any reason for hiding it either.
The modules do not need dma_buf_allocated_pages, hiding it can prevent the module from calling it. So I think that EXPORT_SYMBOL_GPL is unnecessary. If one day someone want to call it from the module, maybe it’s not too late to export it at that time.
Yeah, that is a rather good point. Only symbols which should be used by modules/drivers should be exported.
Christian.
Thanks.
- #ifdef CONFIG_DEBUG_FS static int dma_buf_debug_show(struct seq_file *s, void *unused) {
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 6fa761c9cc78..ccc7c40c8db7 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -16,6 +16,7 @@ #ifdef CONFIG_CMA #include <linux/cma.h> #endif +#include <linux/dma-buf.h> #include <asm/page.h> #include "internal.h"
@@ -145,7 +146,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v) show_val_kb(m, "CmaFree: ", global_zone_page_state(NR_FREE_CMA_PAGES)); #endif
+#ifdef CONFIG_DMA_SHARED_BUFFER
show_val_kb(m, "DmaBufTotal: ", dma_buf_allocated_pages());+#endif hugetlb_report_meminfo(m);
arch_report_meminfo(m);diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index efdc56b9d95f..5b05816bd2cd 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -507,4 +507,5 @@ int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *, unsigned long); int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map); void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map); +long dma_buf_allocated_pages(void);
#endif /* __DMA_BUF_H__ */
2.17.1