On Sat, Jul 19, 2014 at 08:40:52PM +0900, Satoru Takeuchi wrote: > In addition, I'd like to know your opinion about whether setting > the upper limit of nr_rambuf_pool argument is neccesary or not. 1) If it's a parameter passed from userspace under the control of the sysadmin, then you should just trust the sysadmin to set a sensible value, and only return an error if the value they ask for is unobtainable. Example: dm-ioctl.c copy_params() 2) If certain large values would be useless, leaving no memory for anything else, then you could apply a sensible limit based on the amount of memory available. Example: dm_bufio.c * Memory management policy: * Limit the number of buffers to DM_BUFIO_MEMORY_PERCENT of main memory * or DM_BUFIO_VMALLOC_PERCENT of vmalloc memory (whichever is lower). * Always allocate at least DM_BUFIO_MIN_BUFFERS buffers. Alasdair -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
