NUMA Hotplug emulator
in [Kernel]
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From: Greg KH on 13 May 2010 14:50 On Thu, May 13, 2010 at 11:02:17AM -0700, Dave Hansen wrote: > On Thu, 2010-05-13 at 09:56 -0700, Greg KH wrote: > > On Thu, May 13, 2010 at 08:00:16PM +0800, Shaohui Zheng wrote: > > > hotplug emulator:extend memory probe interface to support NUMA > > > > > > Extend memory probe interface to support an extra paramter nid, > > > the reserved memory can be added into this node if node exists. > > > > > > Add a memory section(128M) to node 3(boots with mem=1024m) > > > > > > echo 0x40000000,3 > memory/probe > > I dunno. If we're going to put multiple values into the file now and > add to the ABI, can we be more explicit about it? > > echo "physical_address=0x40000000 numa_node=3" > memory/probe > > I'd *GREATLY* prefer that over this new syntax. The existing mechanism > is obtuse enough, and the ',3' makes it more so. > > We should have the code around to parse arguments like that, too, since > we use it for the boot command-line. If you are going to be doing something like this, please use configfs, that is what it is designed for, not sysfs. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Greg KH on 13 May 2010 14:50 On Thu, May 13, 2010 at 10:54:52AM -0700, Dave Hansen wrote: > On Thu, 2010-05-13 at 09:55 -0700, Greg KH wrote: > > > Add a sysfs entry "probe" under /sys/devices/system/node/: > > > > > > - to show all fake offlined nodes: > > > $ cat /sys/devices/system/node/probe > > > > > > - to hotadd a fake offlined node, e.g. nodeid is N: > > > $ echo N > /sys/devices/system/node/probe > > > > As you are trying to add a new sysfs file, please create the matching > > Documentation/ABI/ file as well. > > > > Also note that sysfs files are "one value per file", which I don't think > > this file follows, right? > > I think in this case, it was meant to be a list of acceptable parameters > rather than a set of values, kinda like /sys/power/state. Instead, I > guess we could have: > > /sys/devices/system/node/probeable/3 > /sys/devices/system/node/probeable/43 > /sys/devices/system/node/probeable/65 > /sys/devices/system/node/probeable/5145 > > and the knowledge that you need to pick one of those to echo > into /sys/devices/system/node/probe. But, it's a lot more self > explanatory if you 'cat /sys/devices/system/node/probe', and then pick > one of those to echo back into the file. > > Seems like a decent place to violate the "rule". :) How big would this "list" be? What will it look like exactly? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Dave Hansen on 13 May 2010 15:00 On Thu, 2010-05-13 at 11:15 -0700, Greg KH wrote: > > echo "physical_address=0x40000000 numa_node=3" > memory/probe > > > > I'd *GREATLY* prefer that over this new syntax. The existing mechanism > > is obtuse enough, and the ',3' makes it more so. > > > > We should have the code around to parse arguments like that, too, since > > we use it for the boot command-line. > > If you are going to be doing something like this, please use configfs, > that is what it is designed for, not sysfs. That's probably a really good point, especially since configfs didn't even exist when we made this 'probe' file thingy. It never was a great fit for sysfs anyway. -- Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Greg KH on 13 May 2010 15:10 On Thu, May 13, 2010 at 11:49:38AM -0700, Dave Hansen wrote: > On Thu, 2010-05-13 at 11:15 -0700, Greg KH wrote: > > > echo "physical_address=0x40000000 numa_node=3" > memory/probe > > > > > > I'd *GREATLY* prefer that over this new syntax. The existing mechanism > > > is obtuse enough, and the ',3' makes it more so. > > > > > > We should have the code around to parse arguments like that, too, since > > > we use it for the boot command-line. > > > > If you are going to be doing something like this, please use configfs, > > that is what it is designed for, not sysfs. > > That's probably a really good point, especially since configfs didn't > even exist when we made this 'probe' file thingy. It never was a great > fit for sysfs anyway. Really? configfs was added in 2.6.16, when was this probe file added? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Dave Hansen on 13 May 2010 15:20
On Thu, 2010-05-13 at 11:58 -0700, Greg KH wrote: > > That's probably a really good point, especially since configfs didn't > > even exist when we made this 'probe' file thingy. It never was a great > > fit for sysfs anyway. > > Really? configfs was added in 2.6.16, when was this probe file added? $ git name-rev 3947be19 3947be19 tags/v2.6.15-rc1~728^2~12 -- Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |