Re: [f2fs-dev] [PATCH v6 11/16] erofs: Convert compressed files from readpages to readahead

2020-02-18 Thread Gao Xiang
On Mon, Feb 17, 2020 at 10:46:00AM -0800, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" 
> 
> Use the new readahead operation in erofs.
> 
> Signed-off-by: Matthew Wilcox (Oracle) 

It looks good to me, although some further optimization exists
but we could make a straight-forward transform first, and
I haven't tested the whole series for now...
Will test it later.

Acked-by: Gao Xiang 

Thanks,
Gao Xiang

> ---
>  fs/erofs/zdata.c | 29 +
>  1 file changed, 9 insertions(+), 20 deletions(-)
> 
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index 17f45fcb8c5c..7c02015d501d 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -1303,28 +1303,23 @@ static bool should_decompress_synchronously(struct 
> erofs_sb_info *sbi,
>   return nr <= sbi->max_sync_decompress_pages;
>  }
>  
> -static int z_erofs_readpages(struct file *filp, struct address_space 
> *mapping,
> -  struct list_head *pages, unsigned int nr_pages)
> +static void z_erofs_readahead(struct readahead_control *rac)
>  {
> - struct inode *const inode = mapping->host;
> + struct inode *const inode = rac->mapping->host;
>   struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
>  
> - bool sync = should_decompress_synchronously(sbi, nr_pages);
> + bool sync = should_decompress_synchronously(sbi, readahead_count(rac));
>   struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
> - gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
> - struct page *head = NULL;
> + struct page *page, *head = NULL;
>   LIST_HEAD(pagepool);
>  
> - trace_erofs_readpages(mapping->host, lru_to_page(pages)->index,
> -   nr_pages, false);
> + trace_erofs_readpages(inode, readahead_index(rac),
> + readahead_count(rac), false);
>  
> - f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
> -
> - for (; nr_pages; --nr_pages) {
> - struct page *page = lru_to_page(pages);
> + f.headoffset = readahead_offset(rac);
>  
> + readahead_for_each(rac, page) {
>   prefetchw(&page->flags);
> - list_del(&page->lru);
>  
>   /*
>* A pure asynchronous readahead is indicated if
> @@ -1333,11 +1328,6 @@ static int z_erofs_readpages(struct file *filp, struct 
> address_space *mapping,
>*/
>   sync &= !(PageReadahead(page) && !head);
>  
> - if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
> - list_add(&page->lru, &pagepool);
> - continue;
> - }
> -
>   set_page_private(page, (unsigned long)head);
>   head = page;
>   }
> @@ -1366,11 +1356,10 @@ static int z_erofs_readpages(struct file *filp, 
> struct address_space *mapping,
>  
>   /* clean up the remaining free pages */
>   put_pages_list(&pagepool);
> - return 0;
>  }
>  
>  const struct address_space_operations z_erofs_aops = {
>   .readpage = z_erofs_readpage,
> - .readpages = z_erofs_readpages,
> + .readahead = z_erofs_readahead,
>  };
>  
> -- 
> 2.25.0
> 
> 


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[f2fs-dev] [PATCH v6 11/16] erofs: Convert compressed files from readpages to readahead

2020-02-17 Thread Matthew Wilcox
From: "Matthew Wilcox (Oracle)" 

Use the new readahead operation in erofs.

Signed-off-by: Matthew Wilcox (Oracle) 
---
 fs/erofs/zdata.c | 29 +
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 17f45fcb8c5c..7c02015d501d 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1303,28 +1303,23 @@ static bool should_decompress_synchronously(struct 
erofs_sb_info *sbi,
return nr <= sbi->max_sync_decompress_pages;
 }
 
-static int z_erofs_readpages(struct file *filp, struct address_space *mapping,
-struct list_head *pages, unsigned int nr_pages)
+static void z_erofs_readahead(struct readahead_control *rac)
 {
-   struct inode *const inode = mapping->host;
+   struct inode *const inode = rac->mapping->host;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
 
-   bool sync = should_decompress_synchronously(sbi, nr_pages);
+   bool sync = should_decompress_synchronously(sbi, readahead_count(rac));
struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
-   gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
-   struct page *head = NULL;
+   struct page *page, *head = NULL;
LIST_HEAD(pagepool);
 
-   trace_erofs_readpages(mapping->host, lru_to_page(pages)->index,
- nr_pages, false);
+   trace_erofs_readpages(inode, readahead_index(rac),
+   readahead_count(rac), false);
 
-   f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
-
-   for (; nr_pages; --nr_pages) {
-   struct page *page = lru_to_page(pages);
+   f.headoffset = readahead_offset(rac);
 
+   readahead_for_each(rac, page) {
prefetchw(&page->flags);
-   list_del(&page->lru);
 
/*
 * A pure asynchronous readahead is indicated if
@@ -1333,11 +1328,6 @@ static int z_erofs_readpages(struct file *filp, struct 
address_space *mapping,
 */
sync &= !(PageReadahead(page) && !head);
 
-   if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
-   list_add(&page->lru, &pagepool);
-   continue;
-   }
-
set_page_private(page, (unsigned long)head);
head = page;
}
@@ -1366,11 +1356,10 @@ static int z_erofs_readpages(struct file *filp, struct 
address_space *mapping,
 
/* clean up the remaining free pages */
put_pages_list(&pagepool);
-   return 0;
 }
 
 const struct address_space_operations z_erofs_aops = {
.readpage = z_erofs_readpage,
-   .readpages = z_erofs_readpages,
+   .readahead = z_erofs_readahead,
 };
 
-- 
2.25.0



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