From 5857f70c8a62377c2304d8ad27e579881728fc5a Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 4 Mar 2013 14:32:54 -0800 Subject: idr: fix new kernel-doc warnings Fix new kernel-doc warnings in idr: Warning(include/linux/idr.h:113): No description found for parameter 'idr' Warning(include/linux/idr.h:113): Excess function parameter 'idp' description in 'idr_find' Warning(lib/idr.c:232): Excess function parameter 'id' description in 'sub_alloc' Warning(lib/idr.c:232): Excess function parameter 'id' description in 'sub_alloc' Signed-off-by: Randy Dunlap Acked-by: Tejun Heo Signed-off-by: Linus Torvalds --- lib/idr.c | 1 - 1 file changed, 1 deletion(-) (limited to 'lib/idr.c') diff --git a/lib/idr.c b/lib/idr.c index 00739aaf95a2..4f82a284c6a2 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -214,7 +214,6 @@ EXPORT_SYMBOL(idr_pre_get); * sub_alloc - try to allocate an id without growing the tree depth * @idp: idr handle * @starting_id: id to start search at - * @id: pointer to the allocated handle * @pa: idr_layer[MAX_IDR_LEVEL] used as backtrack buffer * @gfp_mask: allocation mask for idr_layer_alloc() * @layer_idr: optional idr passed to idr_layer_alloc() -- cgit v1.2.3 From c8615d3716fe327c2540cf514a34b227dc9b39e8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 13 Mar 2013 14:59:42 -0700 Subject: idr: deprecate idr_pre_get() and idr_get_new[_above]() Now that all in-kernel users are converted to ues the new alloc interface, mark the old interface deprecated. We should be able to remove these in a few releases. Signed-off-by: Tejun Heo Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/idr.h | 66 ++++++++++++++++++++++++++++++++++++++++------------- lib/idr.c | 41 ++++----------------------------- 2 files changed, 55 insertions(+), 52 deletions(-) (limited to 'lib/idr.c') diff --git a/include/linux/idr.h b/include/linux/idr.h index 8c1f81f823c8..2640c7e99e51 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -73,8 +73,6 @@ struct idr { */ void *idr_find_slowpath(struct idr *idp, int id); -int idr_pre_get(struct idr *idp, gfp_t gfp_mask); -int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id); void idr_preload(gfp_t gfp_mask); int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t gfp_mask); int idr_for_each(struct idr *idp, @@ -119,19 +117,6 @@ static inline void *idr_find(struct idr *idr, int id) return idr_find_slowpath(idr, id); } -/** - * idr_get_new - allocate new idr entry - * @idp: idr handle - * @ptr: pointer you want associated with the id - * @id: pointer to the allocated handle - * - * Simple wrapper around idr_get_new_above() w/ @starting_id of zero. - */ -static inline int idr_get_new(struct idr *idp, void *ptr, int *id) -{ - return idr_get_new_above(idp, ptr, 0, id); -} - /** * idr_for_each_entry - iterate over an idr's elements of a given type * @idp: idr handle @@ -143,7 +128,56 @@ static inline int idr_get_new(struct idr *idp, void *ptr, int *id) entry != NULL; \ ++id, entry = (typeof(entry))idr_get_next((idp), &(id))) -void __idr_remove_all(struct idr *idp); /* don't use */ +/* + * Don't use the following functions. These exist only to suppress + * deprecated warnings on EXPORT_SYMBOL()s. + */ +int __idr_pre_get(struct idr *idp, gfp_t gfp_mask); +int __idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id); +void __idr_remove_all(struct idr *idp); + +/** + * idr_pre_get - reserve resources for idr allocation + * @idp: idr handle + * @gfp_mask: memory allocation flags + * + * Part of old alloc interface. This is going away. Use + * idr_preload[_end]() and idr_alloc() instead. + */ +static inline int __deprecated idr_pre_get(struct idr *idp, gfp_t gfp_mask) +{ + return __idr_pre_get(idp, gfp_mask); +} + +/** + * idr_get_new_above - allocate new idr entry above or equal to a start id + * @idp: idr handle + * @ptr: pointer you want associated with the id + * @starting_id: id to start search at + * @id: pointer to the allocated handle + * + * Part of old alloc interface. This is going away. Use + * idr_preload[_end]() and idr_alloc() instead. + */ +static inline int __deprecated idr_get_new_above(struct idr *idp, void *ptr, + int starting_id, int *id) +{ + return __idr_get_new_above(idp, ptr, starting_id, id); +} + +/** + * idr_get_new - allocate new idr entry + * @idp: idr handle + * @ptr: pointer you want associated with the id + * @id: pointer to the allocated handle + * + * Part of old alloc interface. This is going away. Use + * idr_preload[_end]() and idr_alloc() instead. + */ +static inline int __deprecated idr_get_new(struct idr *idp, void *ptr, int *id) +{ + return __idr_get_new_above(idp, ptr, 0, id); +} /** * idr_remove_all - remove all ids from the given idr tree diff --git a/lib/idr.c b/lib/idr.c index 4f82a284c6a2..c6fb8295507b 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -184,20 +184,7 @@ static void idr_mark_full(struct idr_layer **pa, int id) } } -/** - * idr_pre_get - reserve resources for idr allocation - * @idp: idr handle - * @gfp_mask: memory allocation flags - * - * This function should be called prior to calling the idr_get_new* functions. - * It preallocates enough memory to satisfy the worst possible allocation. The - * caller should pass in GFP_KERNEL if possible. This of course requires that - * no spinning locks be held. - * - * If the system is REALLY out of memory this function returns %0, - * otherwise %1. - */ -int idr_pre_get(struct idr *idp, gfp_t gfp_mask) +int __idr_pre_get(struct idr *idp, gfp_t gfp_mask) { while (idp->id_free_cnt < MAX_IDR_FREE) { struct idr_layer *new; @@ -208,7 +195,7 @@ int idr_pre_get(struct idr *idp, gfp_t gfp_mask) } return 1; } -EXPORT_SYMBOL(idr_pre_get); +EXPORT_SYMBOL(__idr_pre_get); /** * sub_alloc - try to allocate an id without growing the tree depth @@ -375,25 +362,7 @@ static void idr_fill_slot(struct idr *idr, void *ptr, int id, idr_mark_full(pa, id); } -/** - * idr_get_new_above - allocate new idr entry above or equal to a start id - * @idp: idr handle - * @ptr: pointer you want associated with the id - * @starting_id: id to start search at - * @id: pointer to the allocated handle - * - * This is the allocate id function. It should be called with any - * required locks. - * - * If allocation from IDR's private freelist fails, idr_get_new_above() will - * return %-EAGAIN. The caller should retry the idr_pre_get() call to refill - * IDR's preallocation and then retry the idr_get_new_above() call. - * - * If the idr is full idr_get_new_above() will return %-ENOSPC. - * - * @id returns a value in the range @starting_id ... %0x7fffffff - */ -int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id) +int __idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id) { struct idr_layer *pa[MAX_IDR_LEVEL + 1]; int rv; @@ -406,7 +375,7 @@ int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id) *id = rv; return 0; } -EXPORT_SYMBOL(idr_get_new_above); +EXPORT_SYMBOL(__idr_get_new_above); /** * idr_preload - preload for idr_alloc() @@ -907,7 +876,7 @@ static void free_bitmap(struct ida *ida, struct ida_bitmap *bitmap) int ida_pre_get(struct ida *ida, gfp_t gfp_mask) { /* allocate idr_layers */ - if (!idr_pre_get(&ida->idr, gfp_mask)) + if (!__idr_pre_get(&ida->idr, gfp_mask)) return 0; /* allocate free_bitmap */ -- cgit v1.2.3 From 59bfbcf01967d4d3370a2b8294673dd709e732cc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 13 Mar 2013 14:59:49 -0700 Subject: idr: idr_alloc() shouldn't trigger lowmem warning when preloaded GFP_NOIO is often used for idr_alloc() inside preloaded section as the allocation mask doesn't really matter. If the idr tree needs to be expanded, idr_alloc() first tries to allocate using the specified allocation mask and if it fails falls back to the preloaded buffer. This order prevent non-preloading idr_alloc() users from taking advantage of preloading ones by using preload buffer without filling it shifting the burden of allocation to the preload users. Unfortunately, this allowed/expected-to-fail kmem_cache allocation ends up generating spurious slab lowmem warning before succeeding the request from the preload buffer. This patch makes idr_layer_alloc() add __GFP_NOWARN to the first kmem_cache attempt and try kmem_cache again w/o __GFP_NOWARN after allocation from preload_buffer fails so that lowmem warning is generated if not suppressed by the original @gfp_mask. Signed-off-by: Tejun Heo Reported-by: David Teigland Tested-by: David Teigland Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/idr.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) (limited to 'lib/idr.c') diff --git a/lib/idr.c b/lib/idr.c index c6fb8295507b..322e2816f2fb 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -106,8 +106,14 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr) if (layer_idr) return get_from_free_list(layer_idr); - /* try to allocate directly from kmem_cache */ - new = kmem_cache_zalloc(idr_layer_cache, gfp_mask); + /* + * Try to allocate directly from kmem_cache. We want to try this + * before preload buffer; otherwise, non-preloading idr_alloc() + * users will end up taking advantage of preloading ones. As the + * following is allowed to fail for preloaded cases, suppress + * warning this time. + */ + new = kmem_cache_zalloc(idr_layer_cache, gfp_mask | __GFP_NOWARN); if (new) return new; @@ -115,18 +121,24 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr) * Try to fetch one from the per-cpu preload buffer if in process * context. See idr_preload() for details. */ - if (in_interrupt()) - return NULL; - - preempt_disable(); - new = __this_cpu_read(idr_preload_head); - if (new) { - __this_cpu_write(idr_preload_head, new->ary[0]); - __this_cpu_dec(idr_preload_cnt); - new->ary[0] = NULL; + if (!in_interrupt()) { + preempt_disable(); + new = __this_cpu_read(idr_preload_head); + if (new) { + __this_cpu_write(idr_preload_head, new->ary[0]); + __this_cpu_dec(idr_preload_cnt); + new->ary[0] = NULL; + } + preempt_enable(); + if (new) + return new; } - preempt_enable(); - return new; + + /* + * Both failed. Try kmem_cache again w/o adding __GFP_NOWARN so + * that memory allocation failure warning is printed as intended. + */ + return kmem_cache_zalloc(idr_layer_cache, gfp_mask); } static void idr_layer_rcu_free(struct rcu_head *head) -- cgit v1.2.3