mm: vmalloc failure flush fix

An initial vmalloc failure should start off a synchronous flush of lazy areas, in case someone is in progress flushing them already, which could cause us to return an allocation failure even if there is plenty of KVA free. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmalloc failure flush fix
An initial vmalloc failure should start off a synchronous flush of lazy areas, in case someone is in progress flushing them already, which could cause us to return an allocation failure even if there is plenty of KVA free. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin · Linus Torvalds
1 parent f011c2dae6
Showing 1 changed file with 13 additions and 2 deletions Side-by-side Diff
mm/vmalloc.c
@@ -522,13 +522,24 @@
 }
  
 /*
+ * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
+ * is already purging.
+ */
+static void try_purge_vmap_area_lazy(void)
+{
+	unsigned long start = ULONG_MAX, end = 0;
+
+	__purge_vmap_area_lazy(&start, &end, 0, 0);
+}
+
+/*
  * Kick off a purge of the outstanding lazy areas.
  */
 static void purge_vmap_area_lazy(void)
 {
 	unsigned long start = ULONG_MAX, end = 0;
  
-	__purge_vmap_area_lazy(&start, &end, 0, 0);
+	__purge_vmap_area_lazy(&start, &end, 1, 0);
 }
  
 /*
@@ -539,7 +550,7 @@
 	va->flags |= VM_LAZY_FREE;
 	atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
 	if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
-		purge_vmap_area_lazy();
+		try_purge_vmap_area_lazy();
 }
  
 static struct vmap_area *find_vmap_area(unsigned long addr)
...	...	@@ -522,13 +522,24 @@
522	522	}
523	523
524	524	/*
	525	+ * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
	526	+ * is already purging.
	527	+ */
	528	+static void try_purge_vmap_area_lazy(void)
	529	+{
	530	+ unsigned long start = ULONG_MAX, end = 0;
	531	+
	532	+ __purge_vmap_area_lazy(&start, &end, 0, 0);
	533	+}
	534	+
	535	+/*
525	536	* Kick off a purge of the outstanding lazy areas.
526	537	*/
527	538	static void purge_vmap_area_lazy(void)
528	539	{
529	540	unsigned long start = ULONG_MAX, end = 0;
530	541
531		- __purge_vmap_area_lazy(&start, &end, 0, 0);
	542	+ __purge_vmap_area_lazy(&start, &end, 1, 0);
532	543	}
533	544
534	545	/*
...	...	@@ -539,7 +550,7 @@
539	550	va->flags \|= VM_LAZY_FREE;
540	551	atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
541	552	if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
542		- purge_vmap_area_lazy();
	553	+ try_purge_vmap_area_lazy();
543	554	}
544	555
545	556	static struct vmap_area *find_vmap_area(unsigned long addr)