Daniel Pittman <daniel@rimspace.net> wrote:
>
> > What do you think?
>
> I will apply the patch and test later today. This, however, looks like
> a *really* good thing to me.
I think so too.
A possible enhancement is to only do the flush if the backing queue is not
write-congested. So the syscall will very probably be async. If the queue
is write congested then it's a sure bet that someone else is saturating the
disk ayway. We don't want to block in that case.
25-akpm/include/linux/fs.h | 1 +
25-akpm/mm/fadvise.c | 2 ++
25-akpm/mm/filemap.c | 18 ++++++++++++++++--
3 files changed, 19 insertions(+), 2 deletions(-)
diff -puN include/linux/fs.h~fadvise-flush-data include/linux/fs.h
--- 25/include/linux/fs.h~fadvise-flush-data Mon Mar 31 17:03:39 2003
+++ 25-akpm/include/linux/fs.h Mon Mar 31 17:43:45 2003
@@ -1112,6 +1112,7 @@ unsigned long invalidate_inode_pages(str
extern void invalidate_inode_pages2(struct address_space *mapping);
extern void write_inode_now(struct inode *, int);
extern int filemap_fdatawrite(struct address_space *);
+extern int filemap_flush(struct address_space *);
extern int filemap_fdatawait(struct address_space *);
extern void sync_supers(void);
extern void sync_filesystems(int wait);
diff -puN mm/fadvise.c~fadvise-flush-data mm/fadvise.c
--- 25/mm/fadvise.c~fadvise-flush-data Mon Mar 31 17:03:39 2003
+++ 25-akpm/mm/fadvise.c Mon Mar 31 17:44:49 2003
@@ -61,6 +61,8 @@ long sys_fadvise64(int fd, loff_t offset
ret = 0;
break;
case POSIX_FADV_DONTNEED:
+ if (!bdi_write_congested(mapping->backing_dev_info))
+ filemap_flush(mapping);
invalidate_mapping_pages(mapping, offset >> PAGE_CACHE_SHIFT,
(len >> PAGE_CACHE_SHIFT) + 1);
break;
diff -puN mm/filemap.c~fadvise-flush-data mm/filemap.c
--- 25/mm/filemap.c~fadvise-flush-data Mon Mar 31 17:03:39 2003
+++ 25-akpm/mm/filemap.c Mon Mar 31 17:03:39 2003
@@ -122,11 +122,11 @@ static inline int sync_page(struct page
* if a dirty page/buffer is encountered, it must be waited upon, and not just
* skipped over.
*/
-int filemap_fdatawrite(struct address_space *mapping)
+static int __filemap_fdatawrite(struct address_space *mapping, int sync_mode)
{
int ret;
struct writeback_control wbc = {
- .sync_mode = WB_SYNC_ALL,
+ .sync_mode = sync_mode,
.nr_to_write = mapping->nrpages * 2,
};
@@ -140,6 +140,20 @@ int filemap_fdatawrite(struct address_sp
return ret;
}
+int filemap_fdatawrite(struct address_space *mapping)
+{
+ return __filemap_fdatawrite(mapping, WB_SYNC_ALL);
+}
+
+/*
+ * This is a mostly non-blocking flush. Not suitable for data-integrity
+ * purposes.
+ */
+int filemap_flush(struct address_space *mapping)
+{
+ return __filemap_fdatawrite(mapping, WB_SYNC_NONE);
+}
+
/**
* filemap_fdatawait - walk the list of locked pages of the given address
* space and wait for all of them.
_
-
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This archive was generated by hypermail 2b29 : Mon Mar 31 2003 - 22:00:38 EST