From d5d14ed6f2db7287a5088e1350cf422bf72140b3 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 29 Mar 2012 13:58:43 -0400 Subject: arch/tile: Allow tilegx to build with either 16K or 64K page size This change introduces new flags for the hv_install_context() API that passes a page table pointer to the hypervisor. Clients can explicitly request 4K, 16K, or 64K small pages when they install a new context. In practice, the page size is fixed at kernel compile time and the same size is always requested every time a new page table is installed. The header changes so that it provides more abstract macros for managing "page" things like PFNs and page tables. For example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old HV_PAGE_SIZE_SMALL. The various PFN routines have been eliminated and only PA- or PTFN-based ones remain (since PTFNs are always expressed in fixed 2KB "page" size). The page-table management macros are renamed with a leading underscore and take page-size arguments with the presumption that clients will use those macros in some single place to provide the "real" macros they will use themselves. I happened to notice the old hv_set_caching() API was totally broken (it assumed 4KB pages) so I changed it so it would nominally work correctly with other page sizes. Tag modules with the page size so you can't load a module built with a conflicting page size. (And add a test for SMP while we're at it.) Signed-off-by: Chris Metcalf --- arch/tile/Kconfig | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'arch/tile/Kconfig') diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig index 74239dd77e0..38c3957e0b4 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -139,6 +139,31 @@ config NR_CPUS smaller kernel memory footprint results from using a smaller value on chips with fewer tiles. +if TILEGX + +choice + prompt "Kernel page size" + default PAGE_SIZE_64KB + help + This lets you select the page size of the kernel. For best + performance on memory-intensive applications, a page size of 64KB + is recommended. For workloads involving many small files, many + connections, etc., it may be better to select 16KB, which uses + memory more efficiently at some cost in TLB performance. + + Note that this option is TILE-Gx specific; currently + TILEPro page size is set by rebuilding the hypervisor. + +config PAGE_SIZE_16KB + bool "16KB" + +config PAGE_SIZE_64KB + bool "64KB" + +endchoice + +endif + source "kernel/time/Kconfig" source "kernel/Kconfig.hz" -- cgit v1.2.3