The patch titled mm: add gfp flags for NODEMASK_ALLOC slab allocations has been removed from the -mm tree. Its filename was mm-add-gfp-flags-for-nodemask_alloc-slab-allocations.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mm: add gfp flags for NODEMASK_ALLOC slab allocations From: David Rientjes <rientjes@xxxxxxxxxx> Objects passed to NODEMASK_ALLOC() are relatively small in size and are backed by slab caches that are not of large order, traditionally never greater than PAGE_ALLOC_COSTLY_ORDER. Thus, using GFP_KERNEL for these allocations on large machines when CONFIG_NODES_SHIFT > 8 will cause the page allocator to loop endlessly in the allocation attempt, each time invoking both direct reclaim or the oom killer. This is of particular interest when using NODEMASK_ALLOC() from a mempolicy context (either directly in mm/mempolicy.c or the mempolicy constrained hugetlb allocations) since the oom killer always kills current when allocations are constrained by mempolicies. So for all present use cases in the kernel, current would end up being oom killed when direct reclaim fails. That would allow the NODEMASK_ALLOC() to succeed but current would have sacrificed itself upon returning. This patch adds gfp flags to NODEMASK_ALLOC() to pass to kmalloc() on CONFIG_NODES_SHIFT > 8; this parameter is a nop on other configurations. All current use cases either directly from hugetlb code or indirectly via NODEMASK_SCRATCH() union __GFP_NORETRY to avoid direct reclaim and the oom killer when the slab allocator needs to allocate additional pages. The side-effect of this change is that all current use cases of either NODEMASK_ALLOC() or NODEMASK_SCRATCH() need appropriate -ENOMEM handling when the allocation fails (never for CONFIG_NODES_SHIFT <= 8). All current use cases were audited and do have appropriate error handling at this time. Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx> Cc: Mel Gorman <mel@xxxxxxxxx> Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx> Cc: Nishanth Aravamudan <nacc@xxxxxxxxxx> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Adam Litke <agl@xxxxxxxxxx> Cc: Andy Whitcroft <apw@xxxxxxxxxxxxx> Cc: Eric Whitney <eric.whitney@xxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/nodemask.h | 21 ++++++++++++--------- mm/hugetlb.c | 5 +++-- 2 files changed, 15 insertions(+), 11 deletions(-) diff -puN include/linux/nodemask.h~mm-add-gfp-flags-for-nodemask_alloc-slab-allocations include/linux/nodemask.h --- a/include/linux/nodemask.h~mm-add-gfp-flags-for-nodemask_alloc-slab-allocations +++ a/include/linux/nodemask.h @@ -485,15 +485,17 @@ static inline int num_node_state(enum no #define for_each_online_node(node) for_each_node_state(node, N_ONLINE) /* - * For nodemask scrach area.(See CPUMASK_ALLOC() in cpumask.h) - * NODEMASK_ALLOC(x, m) allocates an object of type 'x' with the name 'm'. + * For nodemask scrach area. + * NODEMASK_ALLOC(type, name) allocates an object with a specified type and + * name. */ -#if NODES_SHIFT > 8 /* nodemask_t > 64 bytes */ -#define NODEMASK_ALLOC(x, m) x *m = kmalloc(sizeof(*m), GFP_KERNEL) -#define NODEMASK_FREE(m) kfree(m) +#if NODES_SHIFT > 8 /* nodemask_t > 256 bytes */ +#define NODEMASK_ALLOC(type, name, gfp_flags) \ + type *name = kmalloc(sizeof(*name), gfp_flags) +#define NODEMASK_FREE(m) kfree(m) #else -#define NODEMASK_ALLOC(x, m) x _m, *m = &_m -#define NODEMASK_FREE(m) do {} while (0) +#define NODEMASK_ALLOC(type, name, gfp_flags) type _name, *name = &_name +#define NODEMASK_FREE(m) do {} while (0) #endif /* A example struture for using NODEMASK_ALLOC, used in mempolicy. */ @@ -502,8 +504,9 @@ struct nodemask_scratch { nodemask_t mask2; }; -#define NODEMASK_SCRATCH(x) \ - NODEMASK_ALLOC(struct nodemask_scratch, x) +#define NODEMASK_SCRATCH(x) \ + NODEMASK_ALLOC(struct nodemask_scratch, x, \ + GFP_KERNEL | __GFP_NORETRY) #define NODEMASK_SCRATCH_FREE(x) NODEMASK_FREE(x) diff -puN mm/hugetlb.c~mm-add-gfp-flags-for-nodemask_alloc-slab-allocations mm/hugetlb.c --- a/mm/hugetlb.c~mm-add-gfp-flags-for-nodemask_alloc-slab-allocations +++ a/mm/hugetlb.c @@ -1361,7 +1361,7 @@ static ssize_t nr_hugepages_store_common int nid; unsigned long count; struct hstate *h; - NODEMASK_ALLOC(nodemask_t, nodes_allowed); + NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); err = strict_strtoul(buf, 10, &count); if (err) @@ -1857,7 +1857,8 @@ static int hugetlb_sysctl_handler_common proc_doulongvec_minmax(table, write, buffer, length, ppos); if (write) { - NODEMASK_ALLOC(nodemask_t, nodes_allowed); + NODEMASK_ALLOC(nodemask_t, nodes_allowed, + GFP_KERNEL | __GFP_NORETRY); if (!(obey_mempolicy && init_nodemask_of_mempolicy(nodes_allowed))) { NODEMASK_FREE(nodes_allowed); _ Patches currently in -mm which might be from rientjes@xxxxxxxxxx are origin.patch acpi-remove-nid_inval.patch oom-kill-show-virtual-size-and-rss-information-of-the-killed-process.patch oom-kill-fix-numa-consraint-check-with-nodemask-v42.patch do_wait-optimization-do-not-place-sub-threads-on-task_struct-children-list.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html