[Xen-devel] [PATCH-v2] xen: populate correct number of pages when across mem boundary
From: zhenzhong.duan <hidden>
Date: 2012-07-13 08:31:22
When populate pages across a mem boundary at bootup, the page count populated isn't correct. This is due to mem populated to non-mem region and ignored. Pfn range is also wrongly aligned when mem boundary isn't page aligned. -v2: If xen_do_chunk fail(populate), abort this chunk and any others. Suggested by David, thanks. For a dom0 booted with dom_mem=3368952K(0xcd9ff000-4k) dmesg diff is: [ 0.000000] Freeing 9e-100 pfn range: 98 pages freed [ 0.000000] 1-1 mapping on 9e->100 [ 0.000000] 1-1 mapping on cd9ff->100000 [ 0.000000] Released 98 pages of unused memory [ 0.000000] Set 206435 page(s) to 1-1 mapping -[ 0.000000] Populating cd9fe-cda00 pfn range: 1 pages added +[ 0.000000] Populating cd9fe-cd9ff pfn range: 1 pages added +[ 0.000000] Populating 100000-100061 pfn range: 97 pages added [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] Xen: 0000000000000000 - 000000000009e000 (usable) [ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved) [ 0.000000] Xen: 0000000000100000 - 00000000cd9ff000 (usable) [ 0.000000] Xen: 00000000cd9ffc00 - 00000000cda53c00 (ACPI NVS) ... [ 0.000000] Xen: 0000000100000000 - 0000000100061000 (usable) [ 0.000000] Xen: 0000000100061000 - 000000012c000000 (unusable) ... [ 0.000000] MEMBLOCK configuration: ... -[ 0.000000] reserved[0x4] [0x000000cd9ff000-0x000000cd9ffbff], 0xc00 bytes -[ 0.000000] reserved[0x5] [0x00000100000000-0x00000100060fff], 0x61000 bytes Related xen memory layout: (XEN) Xen-e820 RAM map: (XEN) 0000000000000000 - 000000000009ec00 (usable) (XEN) 00000000000f0000 - 0000000000100000 (reserved) (XEN) 0000000000100000 - 00000000cd9ffc00 (usable) Signed-off-by: Zhenzhong Duan<redacted> ---
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index a4790bf..ead8557 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c@@ -157,25 +157,24 @@ static unsigned long __init xen_populate_chunk( unsigned long dest_pfn; for (i = 0, entry = list; i< map_size; i++, entry++) { - unsigned long credits = credits_left; unsigned long s_pfn; unsigned long e_pfn; unsigned long pfns; long capacity; - if (credits<= 0) + if (credits_left<= 0) break; if (entry->type != E820_RAM) continue; - e_pfn = PFN_UP(entry->addr + entry->size); + e_pfn = PFN_DOWN(entry->addr + entry->size); /* We only care about E820 after the xen_start_info->nr_pages */ if (e_pfn<= max_pfn) continue; - s_pfn = PFN_DOWN(entry->addr); + s_pfn = PFN_UP(entry->addr); /* If the E820 falls within the nr_pages, we want to start * at the nr_pages PFN. * If that would mean going past the E820 entry, skip it
@@ -184,23 +183,19 @@ static unsigned long __init xen_populate_chunk( capacity = e_pfn - max_pfn; dest_pfn = max_pfn; } else { - /* last_pfn MUST be within E820_RAM regions */ - if (*last_pfn&& e_pfn>= *last_pfn) - s_pfn = *last_pfn; capacity = e_pfn - s_pfn; dest_pfn = s_pfn; } - /* If we had filled this E820_RAM entry, go to the next one. */ - if (capacity<= 0) - continue; - if (credits> capacity) - credits = capacity; + if (credits_left< capacity) + capacity = credits_left; - pfns = xen_do_chunk(dest_pfn, dest_pfn + credits, false); + pfns = xen_do_chunk(dest_pfn, dest_pfn + capacity, false); done += pfns; - credits_left -= pfns; *last_pfn = (dest_pfn + pfns); + if (pfns< capacity) + break; + credits_left -= pfns; } return done; }
--
1.7.3