Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH] convert parisc to sparsemem (was Re: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards) | Date | Tue, 26 Apr 2011 09:32:13 +0900 (JST) |
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Hi James,
% make CROSS_COMPILE=hppa64-linux- ARCH=parisc CHK include/linux/version.h CHK include/generated/utsrelease.h CC arch/parisc/kernel/asm-offsets.s In file included from include/linux/topology.h:32:0, from include/linux/sched.h:78, from arch/parisc/kernel/asm-offsets.c:31: include/linux/mmzone.h:916:27: fatal error: asm/sparsemem.h: No such file or directory
Parhaps, you forgot to quilt add?
> This is the preliminary conversion. It's very nasty on parisc because > the memory allocation isn't symmetric anymore: under DISCONTIGMEM, we > push all memory into bootmem and then let free_all_bootmem() do the > magic for us; now we have to do separate initialisations for ranges > because SPARSEMEM can't do multi-range boot memory. It's also got the > horrible hack that I only use the first found range for bootmem. I'm > not sure if this is correct (it won't be if the first found range can be > under about 50MB because we'll run out of bootmem during boot) ... we > might have to sort the ranges and use the larges, but that will involve > us in even more hackery around the bootmem reservations code. > > The boot sequence got a few seconds slower because now all of the loops > over our pfn ranges actually have to skip through the holes (which takes > time for 64GB). > > All in all, I've not been very impressed with SPARSEMEM over > DISCONTIGMEM. It seems to have a lot of rough edges (necessitating > exception code) which DISCONTIGMEM just copes with. > > And before you say the code is smaller, that's because I converted us to > generic show_mem().
Cool! I hoped to remove arch specific show_mem() long time.
And, nitpick comment.
Could you please use #ifdef CONFIG_FLAGMEM instead #ifndef CONFIG_SPARSEMEM? MM gyes parse '#ifndef CONFIG_SPARSEMEM' as valid-both-flatmem-and-discontigmem. but this code isn't.
If my quick grep is correct, all of your #ifndef SPARSEMEM can be converted #ifdef FALTMEM.
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