[PATCH 07/13] ia64: make SPARSEMEM default and disable DISCONTIGMEM

[Mike Rapoport]

On Sat, Dec 12, 2020 at 08:01:44AM -0800, Guenter Roeck wrote:
> On Tue, Oct 27, 2020 at 01:29:49PM +0200, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt at linux.ibm.com>
> > 
> > SPARSEMEM memory model suitable for systems with large holes in their
> > phyiscal memory layout. With SPARSEMEM_VMEMMAP enabled it provides
> > pfn_to_page() and page_to_pfn() as fast as FLATMEM.
> > 
> > Make it the default memory model for IA-64 and disable DISCONTIGMEM which
> > is considered obsolete for quite some time.
> > 
> > Signed-off-by: Mike Rapoport <rppt at linux.ibm.com>
> 
> This patch results in 
> 
> include/linux/mmzone.h:1156:2: error: #error Allocator MAX_ORDER exceeds SECTION_SIZE
>  1156 | #error Allocator MAX_ORDER exceeds SECTION_SIZE
> 
> when building ia64:defconfig.
> 
> Also, PAGE_SHIFT is not defined, though I don't know if that is related.

This is realated as sparesemem.h on ia64 needs PAGE_SHIFT for
SECTION_SIZE and it is not there.
This fixes the build for me (the patch is vs
v5.10-rc7-mmots-2020-12-11-14-43)

diff --git a/arch/ia64/include/asm/sparsemem.h b/arch/ia64/include/asm/sparsemem.h
index dd8c166ffd7b..84652c26f3d9 100644
--- a/arch/ia64/include/asm/sparsemem.h
+++ b/arch/ia64/include/asm/sparsemem.h
@@ -3,6 +3,8 @@
 #define _ASM_IA64_SPARSEMEM_H
 
 #ifdef CONFIG_SPARSEMEM
+#include <asm/page.h>
+
 /*
  * SECTION_SIZE_BITS            2^N: how big each section will be
  * MAX_PHYSMEM_BITS             2^N: how much memory we can have in that space

> Reverting the patch fixes the problem for me.
> 
> Guenter
> 
> ---
> bisect log:
> 
> # bad: [3cc2bd440f2171f093b3a8480a4b54d8c270ed38] Add linux-next specific files for 20201211
> # good: [0477e92881850d44910a7e94fc2c46f96faa131f] Linux 5.10-rc7
> git bisect start 'HEAD' 'v5.10-rc7'
> # good: [0a701401d4e29d9e73f0f3cc02179fc6c9191646] Merge remote-tracking branch 'crypto/master'
> git bisect good 0a701401d4e29d9e73f0f3cc02179fc6c9191646
> # good: [6fd39ad603b113e9c68180b9138084710c036e34] Merge remote-tracking branch 'spi/for-next'
> git bisect good 6fd39ad603b113e9c68180b9138084710c036e34
> # good: [c96b2eec436e87b8c673213b203559bed9e551b9] Merge remote-tracking branch 'vfio/next'
> git bisect good c96b2eec436e87b8c673213b203559bed9e551b9
> # good: [4f2e7f6a2ce4e621b77e59c8763549fa8bee7b4b] Merge remote-tracking branch 'gpio/for-next'
> git bisect good 4f2e7f6a2ce4e621b77e59c8763549fa8bee7b4b
> # good: [5ee06b21caaeb37a1ff5143e8ce91b376fe73dc2] swiotlb.h: add "inline" to swiotlb_adjust_size
> git bisect good 5ee06b21caaeb37a1ff5143e8ce91b376fe73dc2
> # bad: [46aa09d885ce303efd6444def783ec575a5b57ee] mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO
> git bisect bad 46aa09d885ce303efd6444def783ec575a5b57ee
> # good: [3b77356d530bfd93e2450c063718292aa435eede] mm: mmap_lock: add tracepoints around lock acquisition
> git bisect good 3b77356d530bfd93e2450c063718292aa435eede
> # bad: [e0287fb91c006d12bed9e6fbfc7fe661ad7f9647] mm,hwpoison: disable pcplists before grabbing a refcount
> git bisect bad e0287fb91c006d12bed9e6fbfc7fe661ad7f9647
> # bad: [94d171d065be406a2407f0d723afe14c05526283] ia64: make SPARSEMEM default and disable DISCONTIGMEM
> git bisect bad 94d171d065be406a2407f0d723afe14c05526283
> # good: [7499e1e91e18a285274e9b761ba2abf21e4343fa] mm/vmalloc: use free_vm_area() if an allocation fails
> git bisect good 7499e1e91e18a285274e9b761ba2abf21e4343fa
> # good: [eba50fff503fa6d6e20679509a1a960c3e003d22] lib/test_kasan.c: add workqueue test case
> git bisect good eba50fff503fa6d6e20679509a1a960c3e003d22
> # good: [e343d6ff702aaae6181448a38ff85cf201b011ba] ia64: remove 'ifdef CONFIG_ZONE_DMA32' statements
> git bisect good e343d6ff702aaae6181448a38ff85cf201b011ba
> # good: [a0bfb938ae29239a3f13f6a6a4ef41c3c7f0c84c] ia64: split virtual map initialization out of paging_init()
> git bisect good a0bfb938ae29239a3f13f6a6a4ef41c3c7f0c84c
> # good: [0e791e5138cde9b96d34ba68136fd26bb97f81e5] ia64: forbid using VIRTUAL_MEM_MAP with FLATMEM
> git bisect good 0e791e5138cde9b96d34ba68136fd26bb97f81e5
> # first bad commit: [94d171d065be406a2407f0d723afe14c05526283] ia64: make SPARSEMEM default and disable DISCONTIGMEM
> 

-- 
Sincerely yours,
Mike.