From 90e6b677b47ff8c5ba1637941af6b9f92723b003 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 22 Feb 2011 11:10:08 +0100 Subject: [PATCH] x86-64, NUMA: Add proper function comments to global functions Signed-off-by: Tejun Heo Cc: Yinghai Lu Cc: Ingo Molnar --- arch/x86/mm/numa_64.c | 50 +++++++++++++++++++++++++++++++----- arch/x86/mm/numa_emulation.c | 29 ++++++++++++++++++--- 2 files changed, 69 insertions(+), 10 deletions(-) diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c index 45a361b16a59..848381bdd358 100644 --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -205,6 +205,14 @@ static int __init numa_add_memblk_to(int nid, u64 start, u64 end, return 0; } +/** + * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo + * @idx: Index of memblk to remove + * @mi: numa_meminfo to remove memblk from + * + * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and + * decrementing @mi->nr_blks. + */ void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi) { mi->nr_blks--; @@ -212,6 +220,17 @@ void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi) (mi->nr_blks - idx) * sizeof(mi->blk[0])); } +/** + * numa_add_memblk - Add one numa_memblk to numa_meminfo + * @nid: NUMA node ID of the new memblk + * @start: Start address of the new memblk + * @end: End address of the new memblk + * + * Add a new memblk to the default numa_meminfo. + * + * RETURNS: + * 0 on success, -errno on failure. + */ int __init numa_add_memblk(int nid, u64 start, u64 end) { return numa_add_memblk_to(nid, start, end, &numa_meminfo); @@ -263,6 +282,16 @@ setup_node_bootmem(int nodeid, unsigned long start, unsigned long end) node_set_online(nodeid); } +/** + * numa_cleanup_meminfo - Cleanup a numa_meminfo + * @mi: numa_meminfo to clean up + * + * Sanitize @mi by merging and removing unncessary memblks. Also check for + * conflicts and clear unused memblks. + * + * RETURNS: + * 0 on success, -errno on failure. + */ int __init numa_cleanup_meminfo(struct numa_meminfo *mi) { const u64 low = 0; @@ -353,9 +382,11 @@ static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask, node_set(mi->blk[i].nid, *nodemask); } -/* - * Reset distance table. The current table is freed. The next - * numa_set_distance() call will create a new one. +/** + * numa_reset_distance - Reset NUMA distance table + * + * The current table is freed. The next numa_set_distance() call will + * create a new one. */ void __init numa_reset_distance(void) { @@ -370,10 +401,15 @@ void __init numa_reset_distance(void) numa_distance = NULL; } -/* - * Set the distance between node @from to @to to @distance. If distance - * table doesn't exist, one which is large enough to accomodate all the - * currently known nodes will be created. +/** + * numa_set_distance - Set NUMA distance from one NUMA to another + * @from: the 'from' node to set distance + * @to: the 'to' node to set distance + * @distance: NUMA distance + * + * Set the distance from node @from to @to to @distance. If distance table + * doesn't exist, one which is large enough to accomodate all the currently + * known nodes will be created. */ void __init numa_set_distance(int from, int to, int distance) { diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index 23fa2d00253a..607a2e8bc87a 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -267,9 +267,32 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei, return 0; } -/* - * Sets up the system RAM area from start_pfn to last_pfn according to the - * numa=fake command-line option. +/** + * numa_emulation - Emulate NUMA nodes + * @numa_meminfo: NUMA configuration to massage + * @numa_dist_cnt: The size of the physical NUMA distance table + * + * Emulate NUMA nodes according to the numa=fake kernel parameter. + * @numa_meminfo contains the physical memory configuration and is modified + * to reflect the emulated configuration on success. @numa_dist_cnt is + * used to determine the size of the physical distance table. + * + * On success, the following modifications are made. + * + * - @numa_meminfo is updated to reflect the emulated nodes. + * + * - __apicid_to_node[] is updated such that APIC IDs are mapped to the + * emulated nodes. + * + * - NUMA distance table is rebuilt to represent distances between emulated + * nodes. The distances are determined considering how emulated nodes + * are mapped to physical nodes and match the actual distances. + * + * - emu_nid_to_phys[] reflects how emulated nodes are mapped to physical + * nodes. This is used by numa_add_cpu() and numa_remove_cpu(). + * + * If emulation is not enabled or fails, emu_nid_to_phys[] is filled with + * identity mapping and no other modification is made. */ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) {