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(-) >>> ------------------------------------------------------------------------------ HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions Find What Matters Most in Your Big Data with HPCC Systems Open Source. Fast. Scalable. Simple. Ideal for Dirty Data. Leverages Graph Analysis for Fast Processing & Easy Data Exploration http://p.sf.net/sfu/hpccsystems _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
