[PATCH] erofs: get rid of ->lru usage
Gao Xiang
hsiangkao at linux.alibaba.com
Fri Oct 22 20:01:20 AEDT 2021
Currently, ->lru is a way to arrange non-LRU pages and has some
in-kernel users. In order to minimize noticable issues of page
reclaim and cache thrashing under high memory presure, limited
temporary pages were all chained with ->lru and can be reused
during the request. However, it seems that ->lru could be removed
when folio is landing.
Let's use page->private to chain temporary pages for now instead
and transform EROFS formally after the topic of the folio / file
page design is finalized.
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Kent Overstreet <kent.overstreet at gmail.com>
Cc: Chao Yu <chao at kernel.org>
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
fs/erofs/compress.h | 11 +++++-----
fs/erofs/decompressor.c | 8 +++----
fs/erofs/decompressor_lzma.c | 2 +-
fs/erofs/internal.h | 9 +++++++-
fs/erofs/pcpubuf.c | 6 +++---
fs/erofs/utils.c | 19 +++++++++++-----
fs/erofs/zdata.c | 42 ++++++++++++++++--------------------
7 files changed, 53 insertions(+), 44 deletions(-)
diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
index 8ea6a9b14962..579406504919 100644
--- a/fs/erofs/compress.h
+++ b/fs/erofs/compress.h
@@ -22,7 +22,7 @@ struct z_erofs_decompress_req {
struct z_erofs_decompressor {
int (*decompress)(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool);
+ struct page **pagepool);
char *name;
};
@@ -64,7 +64,7 @@ static inline bool z_erofs_is_shortlived_page(struct page *page)
return true;
}
-static inline bool z_erofs_put_shortlivedpage(struct list_head *pagepool,
+static inline bool z_erofs_put_shortlivedpage(struct page **pagepool,
struct page *page)
{
if (!z_erofs_is_shortlived_page(page))
@@ -75,8 +75,7 @@ static inline bool z_erofs_put_shortlivedpage(struct list_head *pagepool,
put_page(page);
} else {
/* follow the pcluster rule above. */
- set_page_private(page, 0);
- list_add(&page->lru, pagepool);
+ erofs_pagepool_add(pagepool, page);
}
return true;
}
@@ -89,9 +88,9 @@ static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
}
int z_erofs_decompress(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool);
+ struct page **pagepool);
/* prototypes for specific algorithms */
int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool);
+ struct page **pagepool);
#endif
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 8a624d73c185..a0786b95cdf9 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -57,7 +57,7 @@ int z_erofs_load_lz4_config(struct super_block *sb,
* all physical pages are consecutive, which can be seen for moderate CR.
*/
static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+ struct page **pagepool)
{
const unsigned int nr =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -254,7 +254,7 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq,
}
static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+ struct page **pagepool)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -296,7 +296,7 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
}
static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+ struct page **pagepool)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -352,7 +352,7 @@ static struct z_erofs_decompressor decompressors[] = {
};
int z_erofs_decompress(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+ struct page **pagepool)
{
return decompressors[rq->alg].decompress(rq, pagepool);
}
diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
index bd7d9809ecf7..50045510a1f4 100644
--- a/fs/erofs/decompressor_lzma.c
+++ b/fs/erofs/decompressor_lzma.c
@@ -150,7 +150,7 @@ int z_erofs_load_lzma_config(struct super_block *sb,
}
int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+ struct page **pagepool)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index a6a53d22dfd6..3265688af7f9 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -499,7 +499,14 @@ void erofs_pcpubuf_init(void);
void erofs_pcpubuf_exit(void);
/* utils.c / zdata.c */
-struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
+struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp);
+static inline void erofs_pagepool_add(struct page **pagepool,
+ struct page *page)
+{
+ set_page_private(page, (unsigned long)*pagepool);
+ *pagepool = page;
+}
+void erofs_release_pages(struct page **pagepool);
#ifdef CONFIG_EROFS_FS_ZIP
int erofs_workgroup_put(struct erofs_workgroup *grp);
diff --git a/fs/erofs/pcpubuf.c b/fs/erofs/pcpubuf.c
index 6c885575128a..a2efd833d1b6 100644
--- a/fs/erofs/pcpubuf.c
+++ b/fs/erofs/pcpubuf.c
@@ -49,7 +49,7 @@ int erofs_pcpubuf_growsize(unsigned int nrpages)
{
static DEFINE_MUTEX(pcb_resize_mutex);
static unsigned int pcb_nrpages;
- LIST_HEAD(pagepool);
+ struct page *pagepool = NULL;
int delta, cpu, ret, i;
mutex_lock(&pcb_resize_mutex);
@@ -102,13 +102,13 @@ int erofs_pcpubuf_growsize(unsigned int nrpages)
vunmap(old_ptr);
free_pagearray:
while (i)
- list_add(&oldpages[--i]->lru, &pagepool);
+ erofs_pagepool_add(&pagepool, oldpages[--i]);
kfree(oldpages);
if (ret)
break;
}
pcb_nrpages = nrpages;
- put_pages_list(&pagepool);
+ erofs_release_pages(&pagepool);
out:
mutex_unlock(&pcb_resize_mutex);
return ret;
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index bd86067a63f7..84da2c280012 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -6,20 +6,29 @@
#include "internal.h"
#include <linux/pagevec.h>
-struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
+struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp)
{
- struct page *page;
+ struct page *page = *pagepool;
- if (!list_empty(pool)) {
- page = lru_to_page(pool);
+ if (page) {
DBG_BUGON(page_ref_count(page) != 1);
- list_del(&page->lru);
+ *pagepool = (struct page *)page_private(page);
} else {
page = alloc_page(gfp);
}
return page;
}
+void erofs_release_pages(struct page **pagepool)
+{
+ while (*pagepool) {
+ struct page *page = *pagepool;
+
+ *pagepool = (struct page *)page_private(page);
+ put_page(page);
+ }
+}
+
#ifdef CONFIG_EROFS_FS_ZIP
/* global shrink count (for all mounted EROFS instances) */
static atomic_long_t erofs_global_shrink_cnt;
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index d55e6215cd44..bcb1b91b234f 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -236,7 +236,7 @@ static DEFINE_MUTEX(z_pagemap_global_lock);
static void preload_compressed_pages(struct z_erofs_collector *clt,
struct address_space *mc,
enum z_erofs_cache_alloctype type,
- struct list_head *pagepool)
+ struct page **pagepool)
{
struct z_erofs_pcluster *pcl = clt->pcl;
bool standalone = true;
@@ -287,12 +287,10 @@ static void preload_compressed_pages(struct z_erofs_collector *clt,
if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
continue;
- if (page) {
+ if (page)
put_page(page);
- } else if (newpage) {
- set_page_private(newpage, 0);
- list_add(&newpage->lru, pagepool);
- }
+ else if (newpage)
+ erofs_pagepool_add(pagepool, newpage);
}
/*
@@ -643,7 +641,7 @@ static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
}
static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
- struct page *page, struct list_head *pagepool)
+ struct page *page, struct page **pagepool)
{
struct inode *const inode = fe->inode;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
@@ -836,7 +834,7 @@ static void z_erofs_decompressqueue_endio(struct bio *bio)
static int z_erofs_decompress_pcluster(struct super_block *sb,
struct z_erofs_pcluster *pcl,
- struct list_head *pagepool)
+ struct page **pagepool)
{
struct erofs_sb_info *const sbi = EROFS_SB(sb);
struct z_erofs_pagevec_ctor ctor;
@@ -1036,7 +1034,7 @@ static int z_erofs_decompress_pcluster(struct super_block *sb,
}
static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io,
- struct list_head *pagepool)
+ struct page **pagepool)
{
z_erofs_next_pcluster_t owned = io->head;
@@ -1060,18 +1058,18 @@ static void z_erofs_decompressqueue_work(struct work_struct *work)
{
struct z_erofs_decompressqueue *bgq =
container_of(work, struct z_erofs_decompressqueue, u.work);
- LIST_HEAD(pagepool);
+ struct page *pagepool = NULL;
DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
z_erofs_decompress_queue(bgq, &pagepool);
- put_pages_list(&pagepool);
+ erofs_release_pages(&pagepool);
kvfree(bgq);
}
static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
unsigned int nr,
- struct list_head *pagepool,
+ struct page **pagepool,
struct address_space *mc,
gfp_t gfp)
{
@@ -1173,7 +1171,7 @@ static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
out_allocpage:
page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL);
if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) {
- list_add(&page->lru, pagepool);
+ erofs_pagepool_add(pagepool, page);
cond_resched();
goto repeat;
}
@@ -1257,7 +1255,7 @@ static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
static void z_erofs_submit_queue(struct super_block *sb,
struct z_erofs_decompress_frontend *f,
- struct list_head *pagepool,
+ struct page **pagepool,
struct z_erofs_decompressqueue *fgq,
bool *force_fg)
{
@@ -1365,7 +1363,7 @@ static void z_erofs_submit_queue(struct super_block *sb,
static void z_erofs_runqueue(struct super_block *sb,
struct z_erofs_decompress_frontend *f,
- struct list_head *pagepool, bool force_fg)
+ struct page **pagepool, bool force_fg)
{
struct z_erofs_decompressqueue io[NR_JOBQUEUES];
@@ -1394,7 +1392,7 @@ static void z_erofs_runqueue(struct super_block *sb,
static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
struct readahead_control *rac,
erofs_off_t end,
- struct list_head *pagepool,
+ struct page **pagepool,
bool backmost)
{
struct inode *inode = f->inode;
@@ -1457,8 +1455,8 @@ static int z_erofs_readpage(struct file *file, struct page *page)
{
struct inode *const inode = page->mapping->host;
struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
+ struct page *pagepool = NULL;
int err;
- LIST_HEAD(pagepool);
trace_erofs_readpage(page, false);
f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT;
@@ -1479,8 +1477,7 @@ static int z_erofs_readpage(struct file *file, struct page *page)
if (f.map.mpage)
put_page(f.map.mpage);
- /* clean up the remaining free pages */
- put_pages_list(&pagepool);
+ erofs_release_pages(&pagepool);
return err;
}
@@ -1489,9 +1486,8 @@ static void z_erofs_readahead(struct readahead_control *rac)
struct inode *const inode = rac->mapping->host;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
- struct page *page, *head = NULL;
+ struct page *pagepool = NULL, *head = NULL, *page;
unsigned int nr_pages;
- LIST_HEAD(pagepool);
f.readahead = true;
f.headoffset = readahead_pos(rac);
@@ -1528,9 +1524,7 @@ static void z_erofs_readahead(struct readahead_control *rac)
nr_pages <= sbi->opt.max_sync_decompress_pages);
if (f.map.mpage)
put_page(f.map.mpage);
-
- /* clean up the remaining free pages */
- put_pages_list(&pagepool);
+ erofs_release_pages(&pagepool);
}
const struct address_space_operations z_erofs_aops = {
--
2.24.4
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