On Fri, 09 Aug 2013 18:56:54 +0900 Masami Hiramatsu <masami.hiramatsu...@hitachi.com> wrote:
> (2013/08/09 17:45), Namhyung Kim wrote: > > From: Namhyung Kim <namhyung....@lge.com> > > > > Fetching from user space should be done in a non-atomic context. So > > use a temporary buffer and copy its content to the ring buffer > > atomically. > > > > While at it, use __get_data_size() and store_trace_args() to reduce > > code duplication. > > I just concern using kmalloc() in the event handler. For fetching user > memory which can be swapped out, that is true. But most of the cases, > we can presume that it exists on the physical memory. > What about creating a per cpu buffer when uprobes are registered, and delete them when they are finished? Basically what trace_printk() does if it detects that there are users of trace_printk() in the kernel. Note, it does not deallocate them when finished, as it is never finished until reboot ;-) -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
