Re: [PATCH] x86: remove MEMORY_HOTPLUG_RESERVE related code -v2
From: Mel Gorman
Date: Wed May 13 2009 - 11:00:13 EST
On Tue, May 12, 2009 at 11:13:15PM -0700, Yinghai Lu wrote:
>
> after
> | commit b263295dbffd33b0fbff670720fa178c30e3392a
> | Author: Christoph Lameter <clameter@xxxxxxx>
> | Date: Wed Jan 30 13:30:47 2008 +0100
> |
> | x86: 64-bit, make sparsemem vmemmap the only memory model
>
> we don't have MEMORY_HOTPLUG_RESERVE anymore.
>
> Historically, x86-64 had an architecture-specific method for memory hotplug
> whereby it scanned the SRAT for physical memory ranges that could be
> potentially used for memory hot-add later. By reserving those ranges
> without physical memory, the memmap would be allocated and left dormant
> until needed. This depended on the DISCONTIG memory model which has been
> removed so the code implementing HOTPLUG_RESERVE is now dead.
>
> This patch removes the dead code used by MEMORY_HOTPLUG_RESERVE
>
> Changelog updated by Mel.
>
> v2: updated changelog, and remove hotadd= in doc
>
> [ Impact: remove dead code ]
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
> Cc: Mel Gorman <mel@xxxxxxxxx>
Patch looks good and successfully boot-tested on a small number of
machines. Nice work.
Reviewed-by: Mel Gorman <mel@xxxxxxxxx>
>
> ---
> Documentation/x86/x86_64/boot-options.txt | 5 --
> arch/x86/include/asm/numa_64.h | 3 -
> arch/x86/mm/numa_64.c | 5 --
> arch/x86/mm/srat_64.c | 63 +++++----------------------
> include/linux/mm.h | 2
> mm/page_alloc.c | 69 ------------------------------
> 6 files changed, 12 insertions(+), 135 deletions(-)
>
> Index: linux-2.6/arch/x86/include/asm/numa_64.h
> ===================================================================
> --- linux-2.6.orig/arch/x86/include/asm/numa_64.h
> +++ linux-2.6/arch/x86/include/asm/numa_64.h
> @@ -17,9 +17,6 @@ extern int compute_hash_shift(struct boo
> extern void numa_init_array(void);
> extern int numa_off;
>
> -extern void srat_reserve_add_area(int nodeid);
> -extern int hotadd_percent;
> -
> extern s16 apicid_to_node[MAX_LOCAL_APIC];
>
> extern unsigned long numa_free_all_bootmem(void);
> Index: linux-2.6/arch/x86/mm/numa_64.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/mm/numa_64.c
> +++ linux-2.6/arch/x86/mm/numa_64.c
> @@ -272,9 +272,6 @@ void __init setup_node_bootmem(int nodei
> reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
> bootmap_pages<<PAGE_SHIFT, BOOTMEM_DEFAULT);
>
> -#ifdef CONFIG_ACPI_NUMA
> - srat_reserve_add_area(nodeid);
> -#endif
> node_set_online(nodeid);
> }
>
> @@ -593,8 +590,6 @@ static __init int numa_setup(char *opt)
> #ifdef CONFIG_ACPI_NUMA
> if (!strncmp(opt, "noacpi", 6))
> acpi_numa = -1;
> - if (!strncmp(opt, "hotadd=", 7))
> - hotadd_percent = simple_strtoul(opt+7, NULL, 10);
> #endif
> return 0;
> }
> Index: linux-2.6/arch/x86/mm/srat_64.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/mm/srat_64.c
> +++ linux-2.6/arch/x86/mm/srat_64.c
> @@ -31,8 +31,6 @@ static nodemask_t nodes_parsed __initdat
> static nodemask_t cpu_nodes_parsed __initdata;
> static struct bootnode nodes[MAX_NUMNODES] __initdata;
> static struct bootnode nodes_add[MAX_NUMNODES];
> -static int found_add_area __initdata;
> -int hotadd_percent __initdata = 0;
>
> static int num_node_memblks __initdata;
> static struct bootnode node_memblk_range[NR_NODE_MEMBLKS] __initdata;
> @@ -66,9 +64,6 @@ static __init void cutoff_node(int i, un
> {
> struct bootnode *nd = &nodes[i];
>
> - if (found_add_area)
> - return;
> -
> if (nd->start < start) {
> nd->start = start;
> if (nd->end < nd->start)
> @@ -86,7 +81,6 @@ static __init void bad_srat(void)
> int i;
> printk(KERN_ERR "SRAT: SRAT not used.\n");
> acpi_numa = -1;
> - found_add_area = 0;
> for (i = 0; i < MAX_LOCAL_APIC; i++)
> apicid_to_node[i] = NUMA_NO_NODE;
> for (i = 0; i < MAX_NUMNODES; i++)
> @@ -182,24 +176,21 @@ acpi_numa_processor_affinity_init(struct
> pxm, apic_id, node);
> }
>
> -static int update_end_of_memory(unsigned long end) {return -1;}
> -static int hotadd_enough_memory(struct bootnode *nd) {return 1;}
> #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
> static inline int save_add_info(void) {return 1;}
> #else
> static inline int save_add_info(void) {return 0;}
> #endif
> /*
> - * Update nodes_add and decide if to include add are in the zone.
> - * Both SPARSE and RESERVE need nodes_add information.
> - * This code supports one contiguous hot add area per node.
> + * Update nodes_add[]
> + * This code supports one contiguous hot add area per node
> */
> -static int __init
> -reserve_hotadd(int node, unsigned long start, unsigned long end)
> +static void __init
> +update_nodes_add(int node, unsigned long start, unsigned long end)
> {
> unsigned long s_pfn = start >> PAGE_SHIFT;
> unsigned long e_pfn = end >> PAGE_SHIFT;
> - int ret = 0, changed = 0;
> + int changed = 0;
> struct bootnode *nd = &nodes_add[node];
>
> /* I had some trouble with strange memory hotadd regions breaking
> @@ -210,7 +201,7 @@ reserve_hotadd(int node, unsigned long s
> mistakes */
> if ((signed long)(end - start) < NODE_MIN_SIZE) {
> printk(KERN_ERR "SRAT: Hotplug area too small\n");
> - return -1;
> + return;
> }
>
> /* This check might be a bit too strict, but I'm keeping it for now. */
> @@ -218,12 +209,7 @@ reserve_hotadd(int node, unsigned long s
> printk(KERN_ERR
> "SRAT: Hotplug area %lu -> %lu has existing memory\n",
> s_pfn, e_pfn);
> - return -1;
> - }
> -
> - if (!hotadd_enough_memory(&nodes_add[node])) {
> - printk(KERN_ERR "SRAT: Hotplug area too large\n");
> - return -1;
> + return;
> }
>
> /* Looks good */
> @@ -245,11 +231,9 @@ reserve_hotadd(int node, unsigned long s
> printk(KERN_ERR "SRAT: Hotplug zone not continuous. Partly ignored\n");
> }
>
> - ret = update_end_of_memory(nd->end);
> -
> if (changed)
> - printk(KERN_INFO "SRAT: hot plug zone found %Lx - %Lx\n", nd->start, nd->end);
> - return ret;
> + printk(KERN_INFO "SRAT: hot plug zone found %Lx - %Lx\n",
> + nd->start, nd->end);
> }
>
> /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
> @@ -310,13 +294,10 @@ acpi_numa_memory_affinity_init(struct ac
> start, end);
> e820_register_active_regions(node, start >> PAGE_SHIFT,
> end >> PAGE_SHIFT);
> - push_node_boundaries(node, nd->start >> PAGE_SHIFT,
> - nd->end >> PAGE_SHIFT);
>
> - if ((ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) &&
> - (reserve_hotadd(node, start, end) < 0)) {
> - /* Ignore hotadd region. Undo damage */
> - printk(KERN_NOTICE "SRAT: Hotplug region ignored\n");
> + if (ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) {
> + update_nodes_add(node, start, end);
> + /* restore nodes[node] */
> *nd = oldnode;
> if ((nd->start | nd->end) == 0)
> node_clear(node, nodes_parsed);
> @@ -510,26 +491,6 @@ static int null_slit_node_compare(int a,
> }
> #endif /* CONFIG_NUMA_EMU */
>
> -void __init srat_reserve_add_area(int nodeid)
> -{
> - if (found_add_area && nodes_add[nodeid].end) {
> - u64 total_mb;
> -
> - printk(KERN_INFO "SRAT: Reserving hot-add memory space "
> - "for node %d at %Lx-%Lx\n",
> - nodeid, nodes_add[nodeid].start, nodes_add[nodeid].end);
> - total_mb = (nodes_add[nodeid].end - nodes_add[nodeid].start)
> - >> PAGE_SHIFT;
> - total_mb *= sizeof(struct page);
> - total_mb >>= 20;
> - printk(KERN_INFO "SRAT: This will cost you %Lu MB of "
> - "pre-allocated memory.\n", (unsigned long long)total_mb);
> - reserve_bootmem_node(NODE_DATA(nodeid), nodes_add[nodeid].start,
> - nodes_add[nodeid].end - nodes_add[nodeid].start,
> - BOOTMEM_DEFAULT);
> - }
> -}
> -
> int __node_distance(int a, int b)
> {
> int index;
> Index: linux-2.6/include/linux/mm.h
> ===================================================================
> --- linux-2.6.orig/include/linux/mm.h
> +++ linux-2.6/include/linux/mm.h
> @@ -1032,8 +1032,6 @@ extern void add_active_range(unsigned in
> unsigned long end_pfn);
> extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
> unsigned long end_pfn);
> -extern void push_node_boundaries(unsigned int nid, unsigned long start_pfn,
> - unsigned long end_pfn);
> extern void remove_all_active_ranges(void);
> extern unsigned long absent_pages_in_range(unsigned long start_pfn,
> unsigned long end_pfn);
> Index: linux-2.6/mm/page_alloc.c
> ===================================================================
> --- linux-2.6.orig/mm/page_alloc.c
> +++ linux-2.6/mm/page_alloc.c
> @@ -150,10 +150,6 @@ static unsigned long __meminitdata dma_r
> static int __meminitdata nr_nodemap_entries;
> static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
> static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
> -#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
> - static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES];
> - static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES];
> -#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
> static unsigned long __initdata required_kernelcore;
> static unsigned long __initdata required_movablecore;
> static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
> @@ -3121,64 +3117,6 @@ void __init sparse_memory_present_with_a
> }
>
> /**
> - * push_node_boundaries - Push node boundaries to at least the requested boundary
> - * @nid: The nid of the node to push the boundary for
> - * @start_pfn: The start pfn of the node
> - * @end_pfn: The end pfn of the node
> - *
> - * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
> - * time. Specifically, on x86_64, SRAT will report ranges that can potentially
> - * be hotplugged even though no physical memory exists. This function allows
> - * an arch to push out the node boundaries so mem_map is allocated that can
> - * be used later.
> - */
> -#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
> -void __init push_node_boundaries(unsigned int nid,
> - unsigned long start_pfn, unsigned long end_pfn)
> -{
> - mminit_dprintk(MMINIT_TRACE, "zoneboundary",
> - "Entering push_node_boundaries(%u, %lu, %lu)\n",
> - nid, start_pfn, end_pfn);
> -
> - /* Initialise the boundary for this node if necessary */
> - if (node_boundary_end_pfn[nid] == 0)
> - node_boundary_start_pfn[nid] = -1UL;
> -
> - /* Update the boundaries */
> - if (node_boundary_start_pfn[nid] > start_pfn)
> - node_boundary_start_pfn[nid] = start_pfn;
> - if (node_boundary_end_pfn[nid] < end_pfn)
> - node_boundary_end_pfn[nid] = end_pfn;
> -}
> -
> -/* If necessary, push the node boundary out for reserve hotadd */
> -static void __meminit account_node_boundary(unsigned int nid,
> - unsigned long *start_pfn, unsigned long *end_pfn)
> -{
> - mminit_dprintk(MMINIT_TRACE, "zoneboundary",
> - "Entering account_node_boundary(%u, %lu, %lu)\n",
> - nid, *start_pfn, *end_pfn);
> -
> - /* Return if boundary information has not been provided */
> - if (node_boundary_end_pfn[nid] == 0)
> - return;
> -
> - /* Check the boundaries and update if necessary */
> - if (node_boundary_start_pfn[nid] < *start_pfn)
> - *start_pfn = node_boundary_start_pfn[nid];
> - if (node_boundary_end_pfn[nid] > *end_pfn)
> - *end_pfn = node_boundary_end_pfn[nid];
> -}
> -#else
> -void __init push_node_boundaries(unsigned int nid,
> - unsigned long start_pfn, unsigned long end_pfn) {}
> -
> -static void __meminit account_node_boundary(unsigned int nid,
> - unsigned long *start_pfn, unsigned long *end_pfn) {}
> -#endif
> -
> -
> -/**
> * get_pfn_range_for_nid - Return the start and end page frames for a node
> * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
> * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
> @@ -3203,9 +3141,6 @@ void __meminit get_pfn_range_for_nid(uns
>
> if (*start_pfn == -1UL)
> *start_pfn = 0;
> -
> - /* Push the node boundaries out if requested */
> - account_node_boundary(nid, start_pfn, end_pfn);
> }
>
> /*
> @@ -3810,10 +3745,6 @@ void __init remove_all_active_ranges(voi
> {
> memset(early_node_map, 0, sizeof(early_node_map));
> nr_nodemap_entries = 0;
> -#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
> - memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
> - memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
> -#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
> }
>
> /* Compare two active node_active_regions */
> Index: linux-2.6/Documentation/x86/x86_64/boot-options.txt
> ===================================================================
> --- linux-2.6.orig/Documentation/x86/x86_64/boot-options.txt
> +++ linux-2.6/Documentation/x86/x86_64/boot-options.txt
> @@ -150,11 +150,6 @@ NUMA
> Otherwise, the remaining system RAM is allocated to an
> additional node.
>
> - numa=hotadd=percent
> - Only allow hotadd memory to preallocate page structures upto
> - percent of already available memory.
> - numa=hotadd=0 will disable hotadd memory.
> -
> ACPI
>
> acpi=off Don't enable ACPI
>
--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/