On 02/22/2015 06:27 PM, Christoph Hellwig wrote: > On Thu, Feb 19, 2015 at 11:25:37AM +0200, Boaz Harrosh wrote: >> I do not see why you need the nvdimm_type= kernel option at all. >> >> I have here a script that auto detects any NvDIMM. It works with all >> the chips that I have access to. And Also it has support for if you have >> memmap=sss\$aaa. >> For all these detected regions it will load a pmem device. >> >> It is easy to filter for any type of memory you want. What >> will the (annoying) kernel option give you? >> >> OK I might be jumping the guns, send the patch and I'll look >> at it. > > The kernel option means we can autodetect the nvdimms in kernel space > with just that option set, no need for needing userspace setup. >
Do you mean that pmem is: - Loaded without any parameters. - A new API is defined for enumerating NvDIMMs. pmem uses that for creating new devices. - e820 registers such devices according to special type passed on Kernel command-line. (That could be a Kconfig as well you know, I hate Kernel command-line) (Similar to what very old prd.c did only not hacking the e820 lists directly) > How does your script / patch work? > Easy just parses /proc/iomem + looks at Kernel command line. It has support not only for type-12 memory but also for "reserved" regions, made by memmap=sss$aaa stated on command line. And/or also an /etc/pmem.cfg list of regions. So you can go automatic or manual or a mix of both (And slice a region for xfstests scratch device). In any case it helps to have my patches, but also old Kernels are supported with the BLK_DEV_PMEM_IGNORE_REQUEST_MEM_RET. On old Kernels they are all "reserved" regions, no unknown-12 type. Once a list of regions or split-regions is established pmem is loaded with that list. > I won't be back to my nvdimm enabled hardware until after LSF/MM, > so any work from me in this area will have to wait a bit. > Have a good time. Will you guys have a talk about pmem ? If yes I would love it if you guys can talk about the use-of-pages-with-pmem. Please tell me I can write a looong argument about it. Thanks Boaz -- 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/
