| Message ID | 20210517112044.233138-5-aisheng.dong@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/sparse: a few minor fixes and improvements | expand |
On 17.05.21 13:20, Dong Aisheng wrote: > In order to distinguish the struct mem_section for a better code > readability and align with kernel doc [1] name below, change the > global mem section name to 'mem_sections' from 'mem_section'. > > [1] Documentation/vm/memory-model.rst > "The `mem_section` objects are arranged in a two-dimensional array > called `mem_sections`." > > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Dave Young <dyoung@redhat.com> > Cc: Baoquan He <bhe@redhat.com> > Cc: Vivek Goyal <vgoyal@redhat.com> > Cc: kexec@lists.infradead.org > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > --- > include/linux/mmzone.h | 10 +++++----- > kernel/crash_core.c | 4 ++-- > mm/sparse.c | 16 ++++++++-------- > 3 files changed, 15 insertions(+), 15 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index fc23e36cb165..b348a06915c5 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -1297,9 +1297,9 @@ struct mem_section { > #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) > > #ifdef CONFIG_SPARSEMEM_EXTREME > -extern struct mem_section **mem_section; > +extern struct mem_section **mem_sections; > #else > -extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; > +extern struct mem_section mem_sections[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; > #endif > > static inline unsigned long *section_to_usemap(struct mem_section *ms) > @@ -1310,12 +1310,12 @@ static inline unsigned long *section_to_usemap(struct mem_section *ms) > static inline struct mem_section *__nr_to_section(unsigned long nr) > { > #ifdef CONFIG_SPARSEMEM_EXTREME > - if (!mem_section) > + if (!mem_sections) > return NULL; > #endif > - if (!mem_section[SECTION_NR_TO_ROOT(nr)]) > + if (!mem_sections[SECTION_NR_TO_ROOT(nr)]) > return NULL; > - return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; > + return &mem_sections[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; > } > extern unsigned long __section_nr(struct mem_section *ms); > extern size_t mem_section_usage_size(void); > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 29cc15398ee4..fb1180d81b5a 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -414,8 +414,8 @@ static int __init crash_save_vmcoreinfo_init(void) > VMCOREINFO_SYMBOL(contig_page_data); > #endif > #ifdef CONFIG_SPARSEMEM > - VMCOREINFO_SYMBOL_ARRAY(mem_section); > - VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); > + VMCOREINFO_SYMBOL_ARRAY(mem_sections); > + VMCOREINFO_LENGTH(mem_sections, NR_SECTION_ROOTS); > VMCOREINFO_STRUCT_SIZE(mem_section); > VMCOREINFO_OFFSET(mem_section, section_mem_map); > VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); > diff --git a/mm/sparse.c b/mm/sparse.c > index df4418c12f04..a96e7e65475f 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -24,12 +24,12 @@ > * 1) mem_section - memory sections, mem_map's for valid memory > */ > #ifdef CONFIG_SPARSEMEM_EXTREME > -struct mem_section **mem_section; > +struct mem_section **mem_sections; > #else > -struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] > +struct mem_section mem_sections[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] > ____cacheline_internodealigned_in_smp; > #endif > -EXPORT_SYMBOL(mem_section); > +EXPORT_SYMBOL(mem_sections); > > #ifdef NODE_NOT_IN_PAGE_FLAGS > /* > @@ -91,14 +91,14 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) > * > * The mem_hotplug_lock resolves the apparent race below. > */ > - if (mem_section[root]) > + if (mem_sections[root]) > return 0; > > section = sparse_index_alloc(nid); > if (!section) > return -ENOMEM; > > - mem_section[root] = section; > + mem_sections[root] = section; > > return 0; > } > @@ -131,7 +131,7 @@ unsigned long __section_nr(struct mem_section *ms) > #else > unsigned long __section_nr(struct mem_section *ms) > { > - return (unsigned long)(ms - mem_section[0]); > + return (unsigned long)(ms - mem_sections[0]); > } > #endif > > @@ -286,8 +286,8 @@ static void __init memblocks_present(void) > #ifdef CONFIG_SPARSEMEM_EXTREME > size = sizeof(struct mem_section *) * NR_SECTION_ROOTS; > align = 1 << (INTERNODE_CACHE_SHIFT); > - mem_section = memblock_alloc(size, align); > - if (!mem_section) > + mem_sections = memblock_alloc(size, align); > + if (!mem_sections) > panic("%s: Failed to allocate %lu bytes align=0x%lx\n", > __func__, size, align); > #endif > Smells like unnecessary code churn. I'd rather just fix the doc because it doesn't really improve readability IMHO. Anyhow, just my 2 cents.
On Tue, May 25, 2021 at 3:55 PM David Hildenbrand <david@redhat.com> wrote: > > On 17.05.21 13:20, Dong Aisheng wrote: > > In order to distinguish the struct mem_section for a better code > > readability and align with kernel doc [1] name below, change the > > global mem section name to 'mem_sections' from 'mem_section'. > > > > [1] Documentation/vm/memory-model.rst > > "The `mem_section` objects are arranged in a two-dimensional array > > called `mem_sections`." > > > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Dave Young <dyoung@redhat.com> > > Cc: Baoquan He <bhe@redhat.com> > > Cc: Vivek Goyal <vgoyal@redhat.com> > > Cc: kexec@lists.infradead.org > > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > > --- > > include/linux/mmzone.h | 10 +++++----- > > kernel/crash_core.c | 4 ++-- > > mm/sparse.c | 16 ++++++++-------- > > 3 files changed, 15 insertions(+), 15 deletions(-) > > > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > > index fc23e36cb165..b348a06915c5 100644 > > --- a/include/linux/mmzone.h > > +++ b/include/linux/mmzone.h > > @@ -1297,9 +1297,9 @@ struct mem_section { > > #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) > > > > #ifdef CONFIG_SPARSEMEM_EXTREME > > -extern struct mem_section **mem_section; > > +extern struct mem_section **mem_sections; > > #else > > -extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; > > +extern struct mem_section mem_sections[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; > > #endif > > > > static inline unsigned long *section_to_usemap(struct mem_section *ms) > > @@ -1310,12 +1310,12 @@ static inline unsigned long *section_to_usemap(struct mem_section *ms) > > static inline struct mem_section *__nr_to_section(unsigned long nr) > > { > > #ifdef CONFIG_SPARSEMEM_EXTREME > > - if (!mem_section) > > + if (!mem_sections) > > return NULL; > > #endif > > - if (!mem_section[SECTION_NR_TO_ROOT(nr)]) > > + if (!mem_sections[SECTION_NR_TO_ROOT(nr)]) > > return NULL; > > - return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; > > + return &mem_sections[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; > > } > > extern unsigned long __section_nr(struct mem_section *ms); > > extern size_t mem_section_usage_size(void); > > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > > index 29cc15398ee4..fb1180d81b5a 100644 > > --- a/kernel/crash_core.c > > +++ b/kernel/crash_core.c > > @@ -414,8 +414,8 @@ static int __init crash_save_vmcoreinfo_init(void) > > VMCOREINFO_SYMBOL(contig_page_data); > > #endif > > #ifdef CONFIG_SPARSEMEM > > - VMCOREINFO_SYMBOL_ARRAY(mem_section); > > - VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); > > + VMCOREINFO_SYMBOL_ARRAY(mem_sections); > > + VMCOREINFO_LENGTH(mem_sections, NR_SECTION_ROOTS); > > VMCOREINFO_STRUCT_SIZE(mem_section); > > VMCOREINFO_OFFSET(mem_section, section_mem_map); > > VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); > > diff --git a/mm/sparse.c b/mm/sparse.c > > index df4418c12f04..a96e7e65475f 100644 > > --- a/mm/sparse.c > > +++ b/mm/sparse.c > > @@ -24,12 +24,12 @@ > > * 1) mem_section - memory sections, mem_map's for valid memory > > */ > > #ifdef CONFIG_SPARSEMEM_EXTREME > > -struct mem_section **mem_section; > > +struct mem_section **mem_sections; > > #else > > -struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] > > +struct mem_section mem_sections[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] > > ____cacheline_internodealigned_in_smp; > > #endif > > -EXPORT_SYMBOL(mem_section); > > +EXPORT_SYMBOL(mem_sections); > > > > #ifdef NODE_NOT_IN_PAGE_FLAGS > > /* > > @@ -91,14 +91,14 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) > > * > > * The mem_hotplug_lock resolves the apparent race below. > > */ > > - if (mem_section[root]) > > + if (mem_sections[root]) > > return 0; > > > > section = sparse_index_alloc(nid); > > if (!section) > > return -ENOMEM; > > > > - mem_section[root] = section; > > + mem_sections[root] = section; > > > > return 0; > > } > > @@ -131,7 +131,7 @@ unsigned long __section_nr(struct mem_section *ms) > > #else > > unsigned long __section_nr(struct mem_section *ms) > > { > > - return (unsigned long)(ms - mem_section[0]); > > + return (unsigned long)(ms - mem_sections[0]); > > } > > #endif > > > > @@ -286,8 +286,8 @@ static void __init memblocks_present(void) > > #ifdef CONFIG_SPARSEMEM_EXTREME > > size = sizeof(struct mem_section *) * NR_SECTION_ROOTS; > > align = 1 << (INTERNODE_CACHE_SHIFT); > > - mem_section = memblock_alloc(size, align); > > - if (!mem_section) > > + mem_sections = memblock_alloc(size, align); > > + if (!mem_sections) > > panic("%s: Failed to allocate %lu bytes align=0x%lx\n", > > __func__, size, align); > > #endif > > > > Smells like unnecessary code churn. I'd rather just fix the doc because > it doesn't really improve readability IMHO. > In practice I feel it does affect readability that the global mem_section pointer is mixed with struct mem_section names which results in: 1. hard to quickly jump between global mem_section operation in a single source file. e.g. by VIM hotkey of search 2. hard to quickly identify all global mem_section operations in global source files by tools, e.g. cscope, grep This does cause troubles if users want to quickly go through and understand the code. Regards Aisheng > Anyhow, just my 2 cents. > > -- > Thanks, > > David / dhildenb >
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index fc23e36cb165..b348a06915c5 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1297,9 +1297,9 @@ struct mem_section { #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) #ifdef CONFIG_SPARSEMEM_EXTREME -extern struct mem_section **mem_section; +extern struct mem_section **mem_sections; #else -extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; +extern struct mem_section mem_sections[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; #endif static inline unsigned long *section_to_usemap(struct mem_section *ms) @@ -1310,12 +1310,12 @@ static inline unsigned long *section_to_usemap(struct mem_section *ms) static inline struct mem_section *__nr_to_section(unsigned long nr) { #ifdef CONFIG_SPARSEMEM_EXTREME - if (!mem_section) + if (!mem_sections) return NULL; #endif - if (!mem_section[SECTION_NR_TO_ROOT(nr)]) + if (!mem_sections[SECTION_NR_TO_ROOT(nr)]) return NULL; - return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; + return &mem_sections[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } extern unsigned long __section_nr(struct mem_section *ms); extern size_t mem_section_usage_size(void); diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 29cc15398ee4..fb1180d81b5a 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -414,8 +414,8 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(contig_page_data); #endif #ifdef CONFIG_SPARSEMEM - VMCOREINFO_SYMBOL_ARRAY(mem_section); - VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); + VMCOREINFO_SYMBOL_ARRAY(mem_sections); + VMCOREINFO_LENGTH(mem_sections, NR_SECTION_ROOTS); VMCOREINFO_STRUCT_SIZE(mem_section); VMCOREINFO_OFFSET(mem_section, section_mem_map); VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); diff --git a/mm/sparse.c b/mm/sparse.c index df4418c12f04..a96e7e65475f 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -24,12 +24,12 @@ * 1) mem_section - memory sections, mem_map's for valid memory */ #ifdef CONFIG_SPARSEMEM_EXTREME -struct mem_section **mem_section; +struct mem_section **mem_sections; #else -struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] +struct mem_section mem_sections[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] ____cacheline_internodealigned_in_smp; #endif -EXPORT_SYMBOL(mem_section); +EXPORT_SYMBOL(mem_sections); #ifdef NODE_NOT_IN_PAGE_FLAGS /* @@ -91,14 +91,14 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) * * The mem_hotplug_lock resolves the apparent race below. */ - if (mem_section[root]) + if (mem_sections[root]) return 0; section = sparse_index_alloc(nid); if (!section) return -ENOMEM; - mem_section[root] = section; + mem_sections[root] = section; return 0; } @@ -131,7 +131,7 @@ unsigned long __section_nr(struct mem_section *ms) #else unsigned long __section_nr(struct mem_section *ms) { - return (unsigned long)(ms - mem_section[0]); + return (unsigned long)(ms - mem_sections[0]); } #endif @@ -286,8 +286,8 @@ static void __init memblocks_present(void) #ifdef CONFIG_SPARSEMEM_EXTREME size = sizeof(struct mem_section *) * NR_SECTION_ROOTS; align = 1 << (INTERNODE_CACHE_SHIFT); - mem_section = memblock_alloc(size, align); - if (!mem_section) + mem_sections = memblock_alloc(size, align); + if (!mem_sections) panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align); #endif
In order to distinguish the struct mem_section for a better code readability and align with kernel doc [1] name below, change the global mem section name to 'mem_sections' from 'mem_section'. [1] Documentation/vm/memory-model.rst "The `mem_section` objects are arranged in a two-dimensional array called `mem_sections`." Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: kexec@lists.infradead.org Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> --- include/linux/mmzone.h | 10 +++++----- kernel/crash_core.c | 4 ++-- mm/sparse.c | 16 ++++++++-------- 3 files changed, 15 insertions(+), 15 deletions(-)