| Message ID | 20240615034150.2958-1-richard.weiyang@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] um/mm: remove redundant assignment of max_low_pfn | expand |
On Sat, Jun 15, 2024 at 03:41:50AM +0000, Wei Yang wrote: > Current calculation of max_low_pfn is introduced in commit af84eab20891 > ("[PATCH] uml: fix LVM crash"). It is intended to set max_low_pfn to the > same value as max_pfn. > > But I am not sure why the max_pfn is set to totalram_pages, which > represents the number of usable pages in system instead of an absolute > page frame number. (The change history stops there.) > > While we have already calculate it in setup_physmem(), so not necessary > to do it again. > > Also this would help changing totalram_pages accounting, since we plan > to move the accounting into __free_pages_core(). With this change, > totalram_pages may not represent the total usable pages at this point, > since some pages would be deferred initialized. > > Signed-off-by: Wei Yang <richard.weiyang@gmail.com> > CC: Jeff Dike <jdike@linux.intel.com> > Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> > Cc: Alasdair G Kergon <agk@redhat.com> > CC: Andrew Morton <akpm@linux-foundation.org> > CC: Mike Rapoport (IBM) <rppt@kernel.org> > CC: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> > --- > v2: remove redundant assignment of max_low_pfn > --- > arch/um/kernel/mem.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c > index ca91accd64fc..a5b4fe2ad931 100644 > --- a/arch/um/kernel/mem.c > +++ b/arch/um/kernel/mem.c > @@ -73,7 +73,6 @@ void __init mem_init(void) > > /* this will put all low memory onto the freelists */ > memblock_free_all(); > - max_low_pfn = totalram_pages(); > max_pfn = max_low_pfn; > kmalloc_ok = 1; > } > -- > 2.34.1 >
Would someone pick up this one? On Sat, Jun 15, 2024 at 03:41:50AM +0000, Wei Yang wrote: >Current calculation of max_low_pfn is introduced in commit af84eab20891 >("[PATCH] uml: fix LVM crash"). It is intended to set max_low_pfn to the >same value as max_pfn. > >But I am not sure why the max_pfn is set to totalram_pages, which >represents the number of usable pages in system instead of an absolute >page frame number. (The change history stops there.) > >While we have already calculate it in setup_physmem(), so not necessary >to do it again. > >Also this would help changing totalram_pages accounting, since we plan >to move the accounting into __free_pages_core(). With this change, >totalram_pages may not represent the total usable pages at this point, >since some pages would be deferred initialized. > >Signed-off-by: Wei Yang <richard.weiyang@gmail.com> >CC: Jeff Dike <jdike@linux.intel.com> >Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> >Cc: Alasdair G Kergon <agk@redhat.com> >CC: Andrew Morton <akpm@linux-foundation.org> >CC: Mike Rapoport (IBM) <rppt@kernel.org> >CC: David Hildenbrand <david@redhat.com> > >--- >v2: remove redundant assignment of max_low_pfn >--- > arch/um/kernel/mem.c | 1 - > 1 file changed, 1 deletion(-) > >diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c >index ca91accd64fc..a5b4fe2ad931 100644 >--- a/arch/um/kernel/mem.c >+++ b/arch/um/kernel/mem.c >@@ -73,7 +73,6 @@ void __init mem_init(void) > > /* this will put all low memory onto the freelists */ > memblock_free_all(); >- max_low_pfn = totalram_pages(); > max_pfn = max_low_pfn; > kmalloc_ok = 1; > } >-- >2.34.1
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c index ca91accd64fc..a5b4fe2ad931 100644 --- a/arch/um/kernel/mem.c +++ b/arch/um/kernel/mem.c @@ -73,7 +73,6 @@ void __init mem_init(void) /* this will put all low memory onto the freelists */ memblock_free_all(); - max_low_pfn = totalram_pages(); max_pfn = max_low_pfn; kmalloc_ok = 1; }
Current calculation of max_low_pfn is introduced in commit af84eab20891 ("[PATCH] uml: fix LVM crash"). It is intended to set max_low_pfn to the same value as max_pfn. But I am not sure why the max_pfn is set to totalram_pages, which represents the number of usable pages in system instead of an absolute page frame number. (The change history stops there.) While we have already calculate it in setup_physmem(), so not necessary to do it again. Also this would help changing totalram_pages accounting, since we plan to move the accounting into __free_pages_core(). With this change, totalram_pages may not represent the total usable pages at this point, since some pages would be deferred initialized. Signed-off-by: Wei Yang <richard.weiyang@gmail.com> CC: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Alasdair G Kergon <agk@redhat.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Mike Rapoport (IBM) <rppt@kernel.org> CC: David Hildenbrand <david@redhat.com> --- v2: remove redundant assignment of max_low_pfn --- arch/um/kernel/mem.c | 1 - 1 file changed, 1 deletion(-)