Am 16.06.2014 05:28, schrieb Real Name: > On Sat, Jun 14, 2014 at 11:44:04AM +0200, Richard Weinberger wrote: >> Hi! >> >> Am 03.06.2014 07:30, schrieb Real Name: >>> From: Honggang Li <enjoymind...@gmail.com> >>> >>> The patch based on linux-next-2014-06-02. >>> >>> The old init_maps function does two things: >>> 1) allocates and initializes one struct page array for bootmem >>> 2) count the number of total pages >>> >>> After removed the source code related to the unnecessary array, the name >>> 'init_maps' is some kind of improper named, as it just count the number of >>> total page numbers. So, I renamed the function as 'mem_total_pages'. >>> >>> I tested the patch through repeat reboot the uml kernel many times. >>> [real@name linux-next]$ make ARCH=um defconfig >>> [real@name linux-next]$ make ARCH=um linux >>> [real@name linux-next]$ file linux >>> linux: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically >>> linked (uses shared libs), for GNU/Linux 2.6.32, not stripped >>> [real@name linux-next]$ ./linux >>> ubda=/home/real/linux-next/Fedora20-AMD64-root_fs mem=256m && sync && echo 1 >>> [real@name linux-next]$ ./linux >>> ubda=/home/real/linux-next/Fedora20-AMD64-root_fs mem=256m && sync && echo 2 >>> (repeat reboot the uml kernel many times..) >> >> Can you please include in the changelog the commit sha1 which made the old >> init_maps() obsolete? >> I had a look at the pre-git linux tree, looks like init_maps() wasn't >> touched for more than 10 years. > > hi, richard > > what is the pre-git linux tree? I searched it with google, but failed. > > The v2.6.12 kernel is the oldest one available from the linux-next git tree. > And it has duplicated > struct page arrays. So, any suggestion how to find the commit you wanted?
https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git > linux-2.4.20 + uml-patch-2.4.20-8 works on *old* redhat-9 virtual machine. > And it seems has duplicated > struct page array too. > And if you remove it here too UML still works? Thanks, //richard > The first struct page array > ------------------------ > linux-2.4.20/arch/um/kernel/physmem.c > 157 int init_maps(unsigned long len) > 158 { > 159 struct page *p, *map; > 160 int i, n; > 161 > 162 n = len >> PAGE_SHIFT; > 163 len = n * sizeof(struct page); > 164 > 165 if(kmalloc_ok){ > 166 map = kmalloc(len, GFP_KERNEL); > 167 if(map == NULL) map = vmalloc(len); > 168 } > 169 else map = alloc_bootmem_low_pages(len); > 170 > 171 if(map == NULL) > 172 return(-ENOMEM); > 173 > 174 for(i = 0; i < n; i++){ > 175 p = &map[i]; > 176 set_page_count(p, 0); > 177 SetPageReserved(p); > 178 INIT_LIST_HEAD(&p->list); > 179 } > 180 > 181 mem_map = map; > 182 max_mapnr = n; > 183 return(0); > 184 } > > > The second struct page array > ----------------------- > mm/memory.c > 73 mem_map_t * mem_map; // global define > > mm/page_alloc.c > 839 void __init free_area_init(unsigned long *zones_size) > 840 { > 841 free_area_init_core(0, &contig_page_data, &mem_map, zones_size, > 0, 0, 0); > 842 } > > -------- > mm/page_alloc.c > 685 void __init free_area_init_core(int nid, pg_data_t *pgdat, struct page > **gmap, > 686 unsigned long *zones_size, unsigned long zone_start_paddr, > 687 unsigned long *zholes_size, struct page *lmem_map) > 688 { > ........ > 716 map_size = (totalpages + 1)*sizeof(struct page); > 717 if (lmem_map == (struct page *)0) { > 718 lmem_map = (struct page *) alloc_bootmem_node(pgdat, > map_size); > 719 lmem_map = (struct page *)(PAGE_OFFSET + > 720 MAP_ALIGN((unsigned long)lmem_map - PAGE_OFFSET)); > 721 } > 722 *gmap = pgdat->node_mem_map = lmem_map; > > >> >> Thanks, >> //richard >> >>> Honggang Li (1): >>> delete unnecessary bootmem struct page array >>> >>> arch/um/include/shared/mem_user.h | 2 +- >>> arch/um/kernel/physmem.c | 32 ++++++-------------------------- >>> arch/um/kernel/um_arch.c | 7 +------ >>> 3 files changed, 8 insertions(+), 33 deletions(-) >>> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
