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Message-Id: <20241001075858.48936-8-linyunsheng@huawei.com>
Date: Tue, 1 Oct 2024 15:58:50 +0800
From: Yunsheng Lin <yunshenglin0825@...il.com>
To: davem@...emloft.net,
kuba@...nel.org,
pabeni@...hat.com
Cc: netdev@...r.kernel.org,
linux-kernel@...r.kernel.org,
Yunsheng Lin <linyunsheng@...wei.com>,
Alexander Duyck <alexander.duyck@...il.com>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-mm@...ck.org
Subject: [PATCH net-next v19 07/14] mm: page_frag: some minor refactoring before adding new API
Refactor common codes from __page_frag_alloc_va_align() to
__page_frag_cache_prepare() and __page_frag_cache_commit(),
so that the new API can make use of them.
CC: Alexander Duyck <alexander.duyck@...il.com>
Signed-off-by: Yunsheng Lin <linyunsheng@...wei.com>
---
include/linux/page_frag_cache.h | 36 +++++++++++++++++++++++++++--
mm/page_frag_cache.c | 40 ++++++++++++++++++++++++++-------
2 files changed, 66 insertions(+), 10 deletions(-)
diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h
index 75aaad6eaea2..b634e1338741 100644
--- a/include/linux/page_frag_cache.h
+++ b/include/linux/page_frag_cache.h
@@ -5,6 +5,7 @@
#include <linux/bits.h>
#include <linux/log2.h>
+#include <linux/mmdebug.h>
#include <linux/mm_types_task.h>
#include <linux/types.h>
@@ -41,8 +42,39 @@ static inline bool page_frag_cache_is_pfmemalloc(struct page_frag_cache *nc)
void page_frag_cache_drain(struct page_frag_cache *nc);
void __page_frag_cache_drain(struct page *page, unsigned int count);
-void *__page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz,
- gfp_t gfp_mask, unsigned int align_mask);
+void *__page_frag_cache_prepare(struct page_frag_cache *nc, unsigned int fragsz,
+ struct page_frag *pfrag, gfp_t gfp_mask,
+ unsigned int align_mask);
+unsigned int __page_frag_cache_commit_noref(struct page_frag_cache *nc,
+ struct page_frag *pfrag,
+ unsigned int used_sz);
+
+static inline unsigned int __page_frag_cache_commit(struct page_frag_cache *nc,
+ struct page_frag *pfrag,
+ unsigned int used_sz)
+{
+ VM_BUG_ON(!nc->pagecnt_bias);
+ nc->pagecnt_bias--;
+
+ return __page_frag_cache_commit_noref(nc, pfrag, used_sz);
+}
+
+static inline void *__page_frag_alloc_align(struct page_frag_cache *nc,
+ unsigned int fragsz, gfp_t gfp_mask,
+ unsigned int align_mask)
+{
+ struct page_frag page_frag;
+ void *va;
+
+ va = __page_frag_cache_prepare(nc, fragsz, &page_frag, gfp_mask,
+ align_mask);
+ if (unlikely(!va))
+ return NULL;
+
+ __page_frag_cache_commit(nc, &page_frag, fragsz);
+
+ return va;
+}
static inline void *page_frag_alloc_align(struct page_frag_cache *nc,
unsigned int fragsz, gfp_t gfp_mask,
diff --git a/mm/page_frag_cache.c b/mm/page_frag_cache.c
index cf9375a81a64..6f6e47bbdc8d 100644
--- a/mm/page_frag_cache.c
+++ b/mm/page_frag_cache.c
@@ -95,9 +95,31 @@ void __page_frag_cache_drain(struct page *page, unsigned int count)
}
EXPORT_SYMBOL(__page_frag_cache_drain);
-void *__page_frag_alloc_align(struct page_frag_cache *nc,
- unsigned int fragsz, gfp_t gfp_mask,
- unsigned int align_mask)
+unsigned int __page_frag_cache_commit_noref(struct page_frag_cache *nc,
+ struct page_frag *pfrag,
+ unsigned int used_sz)
+{
+ unsigned int orig_offset;
+
+ VM_BUG_ON(used_sz > pfrag->size);
+ VM_BUG_ON(pfrag->page != page_frag_encoded_page_ptr(nc->encoded_page));
+ VM_BUG_ON(pfrag->offset + pfrag->size >
+ page_frag_cache_page_size(nc->encoded_page));
+
+ /* pfrag->offset might be bigger than the nc->offset due to alignment */
+ VM_BUG_ON(nc->offset > pfrag->offset);
+
+ orig_offset = nc->offset;
+ nc->offset = pfrag->offset + used_sz;
+
+ /* Return true size back to caller considering the offset alignment */
+ return nc->offset - orig_offset;
+}
+EXPORT_SYMBOL(__page_frag_cache_commit_noref);
+
+void *__page_frag_cache_prepare(struct page_frag_cache *nc, unsigned int fragsz,
+ struct page_frag *pfrag, gfp_t gfp_mask,
+ unsigned int align_mask)
{
unsigned long encoded_page = nc->encoded_page;
unsigned int size, offset;
@@ -119,6 +141,8 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc,
/* reset page count bias and offset to start of new frag */
nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
nc->offset = 0;
+ } else {
+ page = page_frag_encoded_page_ptr(encoded_page);
}
size = page_frag_cache_page_size(encoded_page);
@@ -137,8 +161,6 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc,
return NULL;
}
- page = page_frag_encoded_page_ptr(encoded_page);
-
if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
goto refill;
@@ -153,15 +175,17 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc,
/* reset page count bias and offset to start of new frag */
nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
+ nc->offset = 0;
offset = 0;
}
- nc->pagecnt_bias--;
- nc->offset = offset + fragsz;
+ pfrag->page = page;
+ pfrag->offset = offset;
+ pfrag->size = size - offset;
return page_frag_encoded_page_address(encoded_page) + offset;
}
-EXPORT_SYMBOL(__page_frag_alloc_align);
+EXPORT_SYMBOL(__page_frag_cache_prepare);
/*
* Frees a page fragment allocated out of either a compound or order 0 page.
--
2.34.1
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