On 07/21/15 at 09:38am, Ingo Molnar wrote: > > * Dave Young <[email protected]> wrote: > > > Hi, Baoquan > > > > The interface was introduced by Yinghai, ccing him. > > Also, why was this syntax introduced in the first place? Why should the user > care??
The history is like below, I might miss something, Yinghai/HPA/Vivek may correct and provide more background: First commit is below: commit 7d41a8a4a2b2438621a9159477bff36a11d79a42 Author: Yinghai Lu <[email protected]> Date: Thu Jan 24 12:20:10 2013 -0800 x86, kdump: Remove crashkernel range find limit for 64bit Previously kdump reservation is limited to <896M, above commit remove the limitation. Then because of kdump kernel need access low mem for swiotlb buffer, thus there's commit below: commit 0212f9159694be61c6bc52e925fa76643e0c1abf Author: Yinghai Lu <[email protected]> Date: Thu Jan 24 12:20:11 2013 -0800 x86: Add Crash kernel low reservation Later, Vivek found old kexec-tools does not work, then Yinghai introduced new param crashkernel_high=: commit 55a20ee7804ab64ac90bcdd4e2868a42829e2784 Author: Yinghai Lu <[email protected]> Date: Mon Apr 15 22:23:47 2013 -0700 x86, kdump: Retore crashkernel= to allocate under 896M Finally it becomes crashkernel=x,high: commit adbc742bf78695bb98c79d18c558b61571748b99 Author: Yinghai Lu <[email protected]> Date: Mon Apr 15 22:23:48 2013 -0700 x86, kdump: Change crashkernel_high/low= to crashkernel=,high/low > > We should only have a single crashkernel option, to enable it - and > everything > else should be figured out by the kernel, automatically. Presonally I do not current complicated params either, I hope we can have an elegant interface, but seems there's no better way to resolve the low memory only requirement for software tlb. > > Any other sub-options just paper over some fragility elsewhere and make the > feature harder to use, hence more fragile. Agree, it is becoming worse.. Thanks Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
