| Message ID | 1613970095-22577-1-git-send-email-daizhiyuan@phytium.com.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/ioremap: remove volatile keyword in iounmap function | expand |
diff --git a/mm/ioremap.c b/mm/ioremap.c index 5fa1ab4..c49dd41 100644 --- a/mm/ioremap.c +++ b/mm/ioremap.c @@ -281,7 +281,7 @@ void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot) } EXPORT_SYMBOL(ioremap_prot); -void iounmap(volatile void __iomem *addr) +void iounmap(void __iomem *addr) { vunmap((void *)((unsigned long)addr & PAGE_MASK)); }
Like volatile, the kernel primitives which make concurrent access to data safe (spinlocks, mutexes, memory barriers, etc.) are designed to prevent unwanted optimization. If they are being used properly, there will be no need to use volatile as well. If volatile is still necessary, there is almost certainly a bug in the code somewhere. In properly-written kernel code, volatile can only serve to slow things down. see: Documentation/process/volatile-considered-harmful.rst Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> --- mm/ioremap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)