mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-27 11:46:46 -04:00
Code Issues Packages Projects Releases Wiki Activity

mm: replace __GFP_NO_CODETAG with ALLOC_NO_CODETAG

Browse Source 
Now that alloc_pages has an entrypoint that allows passing alloc_flags, we
can take advantage of this to start removing GFP flags that are only used
for mm-internal stuff.

This requires also plumbing the alloc_flags into some more of the
allocator code, in particular __alloc_pages[_noprof]() gets an alloc_flags
arg to go along with its callees, and we now need to pass those flags
deeper into the allocator so they can reach the alloc_tag code.

While moving the flag definition into page_alloc.h, also update the
comment per Hao's suggestion.

No functional change intended.

Link: https://lore.kernel.org/all/b4916118-3537-4e19-8bc8-1d103dd0d225@linux.dev/
Link: https://lore.kernel.org/20260703-alloc-trylock-v5-15-c87b714e19d3@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Tested-by: Hao Ge <hao.ge@linux.dev>
Acked-by: Hao Ge <hao.ge@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Brendan Jackman
2026-07-03 12:31:55 +00:00
committed by Andrew Morton
parent a4f6c0f83d
commit 6372aac4d4
6 changed files with 55 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/alloc_tag.h
View File

@@ -165,11 +165,11 @@ static inline void alloc_tag_sub_check(union codetag_ref *ref)
{
WARN_ONCE(ref && !ref->ct, "alloc_tag was not set\n");
}
void alloc_tag_add_early_pfn(unsigned long pfn, gfp_t gfp_flags);
void alloc_tag_add_early_pfn(unsigned long pfn, unsigned int alloc_flags);
#else
static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) {}
static inline void alloc_tag_sub_check(union codetag_ref *ref) {}
static inline void alloc_tag_add_early_pfn(unsigned long pfn, gfp_t gfp_flags) {}
static inline void alloc_tag_add_early_pfn(unsigned long pfn, unsigned int alloc_flags) {}
#endif
/* Caller should verify both ref and tag to be valid */

23
mm/alloc_tag.c
View File

@@ -15,6 +15,9 @@
#include <linux/vmalloc.h>
#include <linux/kmemleak.h>
#include "internal.h"
#include "page_alloc.h"
#define ALLOCINFO_FILE_NAME "allocinfo"
#define MODULE_ALLOC_TAG_VMAP_SIZE (100000UL * sizeof(struct alloc_tag))
#define SECTION_START(NAME) (CODETAG_SECTION_START_PREFIX NAME)
@@ -792,19 +795,6 @@ struct pfn_pool {
#define PFN_POOL_SIZE ((PAGE_SIZE - offsetof(struct pfn_pool, pfns)) / \
sizeof(unsigned long))
/*
* Skip early PFN recording for a page allocation. Reuses the
* %__GFP_NO_OBJ_EXT bit. Used by __alloc_tag_add_early_pfn() to avoid
* recursion when allocating pages for the early PFN tracking list
* itself.
*
* Codetags of the pages allocated with __GFP_NO_CODETAG should be
* cleared (via clear_page_tag_ref()) before freeing the pages to prevent
* alloc_tag_sub_check() from triggering a warning.
*/
#define __GFP_NO_CODETAG __GFP_NO_OBJ_EXT
static struct pfn_pool *current_pfn_pool __initdata;
static void __init __alloc_tag_add_early_pfn(unsigned long pfn)
@@ -815,7 +805,8 @@ static void __init __alloc_tag_add_early_pfn(unsigned long pfn)
do {
pool = READ_ONCE(current_pfn_pool);
if (!pool || atomic_read(&pool->count) >= PFN_POOL_SIZE) {
struct page *new_page = alloc_page(__GFP_HIGH | __GFP_NO_CODETAG);
struct page *new_page = __alloc_pages(__GFP_HIGH, 0, numa_mem_id(),
NULL, ALLOC_NO_CODETAG);
struct pfn_pool *new;
if (!new_page) {
@@ -846,7 +837,7 @@ typedef void alloc_tag_add_func(unsigned long pfn);
static alloc_tag_add_func __rcu *alloc_tag_add_early_pfn_ptr __refdata =
RCU_INITIALIZER(__alloc_tag_add_early_pfn);
void alloc_tag_add_early_pfn(unsigned long pfn, gfp_t gfp_flags)
void alloc_tag_add_early_pfn(unsigned long pfn, unsigned int alloc_flags)
{
alloc_tag_add_func *alloc_tag_add;
@@ -854,7 +845,7 @@ void alloc_tag_add_early_pfn(unsigned long pfn, gfp_t gfp_flags)
return;
/* Skip allocations for the tracking list itself to avoid recursion. */
if (gfp_flags & __GFP_NO_CODETAG)
if (alloc_flags & ALLOC_NO_CODETAG)
return;
rcu_read_lock();

4
mm/compaction.c
View File

@@ -83,7 +83,7 @@ static inline bool is_via_compact_memory(int order) { return false; }
static struct page *mark_allocated_noprof(struct page *page, unsigned int order, gfp_t gfp_flags)
{
post_alloc_hook(page, order, __GFP_MOVABLE);
post_alloc_hook(page, order, __GFP_MOVABLE, ALLOC_DEFAULT);
set_page_refcounted(page);
return page;
}
@@ -1851,7 +1851,7 @@ static struct folio *compaction_alloc_noprof(struct folio *src, unsigned long da
}
dst = (struct folio *)freepage;
post_alloc_hook(&dst->page, order, __GFP_MOVABLE);
post_alloc_hook(&dst->page, order, __GFP_MOVABLE, ALLOC_DEFAULT);
set_page_refcounted(&dst->page);
if (order)
prep_compound_page(&dst->page, order);

52
mm/page_alloc.c
View File

@@ -1249,7 +1249,7 @@ void __clear_page_tag_ref(struct page *page)
/* Should be called only if mem_alloc_profiling_enabled() */
static noinline
void __pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr, gfp_t gfp_flags)
unsigned int nr, unsigned int alloc_flags)
{
union pgtag_ref_handle handle;
union codetag_ref ref;
@@ -1263,17 +1263,17 @@ void __pgalloc_tag_add(struct page *page, struct task_struct *task,
* page_ext is not available yet, record the pfn so we can
* clear the tag ref later when page_ext is initialized.
*/
alloc_tag_add_early_pfn(page_to_pfn(page), gfp_flags);
alloc_tag_add_early_pfn(page_to_pfn(page), alloc_flags);
if (task->alloc_tag)
alloc_tag_set_inaccurate(task->alloc_tag);
}
}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr, gfp_t gfp_flags)
unsigned int nr, unsigned int alloc_flags)
{
if (mem_alloc_profiling_enabled())
__pgalloc_tag_add(page, task, nr, gfp_flags);
__pgalloc_tag_add(page, task, nr, alloc_flags);
}
/* Should be called only if mem_alloc_profiling_enabled() */
@@ -1306,7 +1306,7 @@ static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr)
#else /* CONFIG_MEM_ALLOC_PROFILING */
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr, gfp_t gfp_flags) {}
unsigned int nr, unsigned int alloc_flags) {}
static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}
static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr) {}
@@ -1810,7 +1810,7 @@ static inline bool should_skip_init(gfp_t flags)
}
inline void post_alloc_hook(struct page *page, unsigned int order,
gfp_t gfp_flags)
gfp_t gfp_flags, unsigned int alloc_flags)
{
const bool zero_tags = gfp_flags & __GFP_ZEROTAGS;
bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags) &&
@@ -1861,13 +1861,13 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
set_page_owner(page, order, gfp_flags);
page_table_check_alloc(page, order);
pgalloc_tag_add(page, current, 1 << order, gfp_flags);
pgalloc_tag_add(page, current, 1 << order, alloc_flags);
}
static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
unsigned int alloc_flags)
{
post_alloc_hook(page, order, gfp_flags);
post_alloc_hook(page, order, gfp_flags, alloc_flags);
if (order && (gfp_flags & __GFP_COMP))
prep_compound_page(page, order);
@@ -4078,7 +4078,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
*/
page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
~__GFP_DIRECT_RECLAIM, order,
ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
ac->alloc_flags|ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
if (page)
goto out;
@@ -4124,7 +4124,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
*/
if (gfp_mask & __GFP_NOFAIL)
page = __alloc_pages_cpuset_fallback(gfp_mask, order,
ALLOC_NO_WATERMARKS, ac);
ac->alloc_flags|ALLOC_NO_WATERMARKS, ac);
}
out:
mutex_unlock(&oom_lock);
@@ -4791,8 +4791,12 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* The fast path uses conservative alloc_flags to succeed only until
* kswapd needs to be woken up, and to avoid the cost of setting up
* alloc_flags precisely. So we do that now.
*
* Can't just or alloc_flags if it contains WMARK bits, but those flags
* shouldn't be set in ac->alloc_flags.
*/
alloc_flags = alloc_flags_slowpath(gfp_mask, order);
VM_WARN_ON(ac->alloc_flags & ALLOC_WMARK_MASK);
alloc_flags = ac->alloc_flags | alloc_flags_slowpath(gfp_mask, order);
/*
* We need to recalculate the starting point for the zonelist iterator
@@ -4834,7 +4838,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
if (reserve_flags)
alloc_flags = alloc_flags_cma(gfp_mask, reserve_flags) |
(alloc_flags & ALLOC_KSWAPD);
ac->alloc_flags | (alloc_flags & ALLOC_KSWAPD);
/*
* Reset the nodemask and zonelist iterators if memory policies can be
@@ -5003,6 +5007,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* we always retry
*/
if (unlikely(nofail)) {
unsigned int alloc_flags = ac->alloc_flags | ALLOC_MIN_RESERVE;
/*
* Lacking direct_reclaim we can't do anything to reclaim memory,
* we disregard these unreasonable nofail requests and still
@@ -5018,7 +5024,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* could deplete whole memory reserves which would just make
* the situation worse.
*/
page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_MIN_RESERVE, ac);
page = __alloc_pages_cpuset_fallback(gfp_mask, order, alloc_flags, ac);
if (page)
goto got_pg;
@@ -5236,7 +5242,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
return nr_populated;
failed:
page = __alloc_pages_noprof(gfp, 0, preferred_nid, nodemask);
page = __alloc_pages_noprof(gfp, 0, preferred_nid, nodemask, ALLOC_DEFAULT);
if (page)
page_array[nr_populated++] = page;
goto out;
@@ -5344,11 +5350,13 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order,
{
struct page *page;
gfp_t alloc_gfp; /* The gfp_t that was actually used for allocation */
struct alloc_context ac = { };
struct alloc_context ac = {
.alloc_flags = alloc_flags,
};
unsigned int fastpath_alloc_flags = alloc_flags;
/* Other flags could be supported later if needed. */
if (WARN_ON(alloc_flags & ~ALLOC_NOLOCK))
if (WARN_ON(alloc_flags & ~(ALLOC_NOLOCK | ALLOC_NO_CODETAG)))
return NULL;
if (!alloc_order_allowed(gfp, order, alloc_flags))
@@ -5421,12 +5429,12 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order,
EXPORT_SYMBOL(__alloc_frozen_pages_noprof);
struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order,
int preferred_nid, nodemask_t *nodemask)
int preferred_nid, nodemask_t *nodemask, unsigned int alloc_flags)
{
struct page *page;
page = __alloc_frozen_pages_noprof(gfp, order, preferred_nid, nodemask,
ALLOC_DEFAULT);
alloc_flags);
if (page)
set_page_refcounted(page);
return page;
@@ -5440,7 +5448,7 @@ struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask, unsigned int order
VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
warn_if_node_offline(nid, gfp_mask);
return __alloc_pages_noprof(gfp_mask, order, nid, NULL);
return __alloc_pages_noprof(gfp_mask, order, nid, NULL, ALLOC_DEFAULT);
}
EXPORT_SYMBOL(alloc_pages_node_noprof);
@@ -5448,7 +5456,7 @@ struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_
nodemask_t *nodemask)
{
struct page *page = __alloc_pages_noprof(gfp | __GFP_COMP, order,
preferred_nid, nodemask);
preferred_nid, nodemask, ALLOC_DEFAULT);
return page_rmappable_folio(page);
}
EXPORT_SYMBOL(__folio_alloc_noprof);
@@ -7130,7 +7138,7 @@ static void split_free_frozen_pages(struct list_head *list, gfp_t gfp_mask)
list_for_each_entry_safe(page, next, &list[order], lru) {
int i;
post_alloc_hook(page, order, gfp_mask);
post_alloc_hook(page, order, gfp_mask, ALLOC_DEFAULT);
if (!order)
continue;
@@ -7335,7 +7343,7 @@ int alloc_contig_frozen_range_noprof(unsigned long start, unsigned long end,
struct page *head = pfn_to_page(start);
check_new_pages(head, order);
prep_new_page(head, order, gfp_mask, 0);
prep_new_page(head, order, gfp_mask, ALLOC_DEFAULT);
} else {
ret = -EINVAL;
WARN(true, "PFN range: requested [%lu, %lu), allocated [%lu, %lu)\n",

14
mm/page_alloc.h
View File

@@ -49,6 +49,13 @@
#define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */
#define ALLOC_NOLOCK 0x400 /* Only use spin_trylock in allocation path */
#define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
/*
* Avoid alloc_tag recursion for internal allocations.
*
* Callers must clear_page_tag_ref() before freeing to avoid warnings from
* alloc_tag_sub_check().
*/
#define ALLOC_NO_CODETAG 0x1000
/* Flags that allow allocations below the min watermark. */
#define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM)
@@ -84,6 +91,8 @@ struct alloc_context {
*/
enum zone_type highest_zoneidx;
bool spread_dirty_pages;
/* Only flags that are global to the whole allocation go here. */
unsigned int alloc_flags;
};
/*
@@ -214,7 +223,8 @@ static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
extern void __free_pages_core(struct page *page, unsigned int order,
enum meminit_context context);
void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags);
void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags,
unsigned int alloc_flags);
extern bool free_pages_prepare(struct page *page, unsigned int order);
extern int user_min_free_kbytes;
@@ -245,7 +255,7 @@ struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned
void free_frozen_pages_nolock(struct page *page, unsigned int order);
struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order, int preferred_nid,
nodemask_t *nodemask);
nodemask_t *nodemask, unsigned int alloc_flags);
#define __alloc_pages(...) alloc_hooks(__alloc_pages_noprof(__VA_ARGS__))
extern void zone_pcp_reset(struct zone *zone);

4
mm/page_frag_cache.c
View File

@@ -57,10 +57,10 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP |
__GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC;
page = __alloc_pages(gfp_mask, PAGE_FRAG_CACHE_MAX_ORDER,
numa_mem_id(), NULL);
numa_mem_id(), NULL, ALLOC_DEFAULT);
#endif
if (unlikely(!page)) {
page = __alloc_pages(gfp, 0, numa_mem_id(), NULL);
page = __alloc_pages(gfp, 0, numa_mem_id(), NULL, ALLOC_DEFAULT);
order = 0;
}