make the page allocator aware of filesystem transactions

In XFS we have large pieces of code that might be called either from inside a filesystem transaction or not. Currently we have added a PF_FSTRANS process flag and fall back to GFP_NOFS when it's set.

I think it might be useful to generalize this at the page allocator level and always clear __GFP_FS if the process flag is set.

Comments?

You can import this changeset into BK by piping this whole message to:
'| bk receive [path to repository]' or apply the patch as usual.

===================================================================

[email protected], 2002-08-23 22:01:27+02:00, [email protected]
VM: make the page allocator aware of filesystem transactions

 include/linux/sched.h |    1 +
 mm/vmscan.c           |    3 +++
 2 files changed, 4 insertions

diff -Nru a/include/linux/sched.h b/include/linux/sched.h
@@ -400,6 +400,7 @@
 #define PF_FREEZE	0x00010000	/* this task should be frozen for suspend */
 #define PF_IOTHREAD	0x00020000	/* this thread is needed for doing I/O to swap */
 #define PF_FROZEN	0x00040000	/* frozen for system suspend */
+#define PF_FSTRANS	0x00080000	/* inside a filesystem transaction */
 
 /*
  * Ptrace flags

diff -Nru a/mm/vmscan.c b/mm/vmscan.c
@@ -458,6 +458,9 @@
 	int max_scan;
 	static atomic_t nr_to_refill = ATOMIC_INIT(0);
 
+	if (current->flags & PF_FSTRANS)
+		gfp_mask &= ~__GFP_FS;
+
 	if (kmem_cache_reap(gfp_mask) >= nr_pages)
   		return 0;
 

===================================================================

This BitKeeper patch contains the following changesets:
1.509
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