2.6.38-stable review patch. If anyone has any objections, please let us know.
------------------ From: Andrew Morton <[email protected]> commit 6d4831c283530a5f2c6bd8172c13efa236eb149d upstream. Azurit reports large increases in system time after 2.6.36 when running Apache. It was bisected down to a892e2d7dcdfa6c76e6 ("vfs: use kmalloc() to allocate fdmem if possible"). That patch caused the vfs to use kmalloc() for very large allocations and this is causing excessive work (and presumably excessive reclaim) within the page allocator. Fix it by falling back to vmalloc() earlier - when the allocation attempt would have been considered "costly" by reclaim. Reported-by: azurIt <[email protected]> Tested-by: azurIt <[email protected]> Acked-by: Changli Gao <[email protected]> Cc: Americo Wang <[email protected]> Cc: Jiri Slaby <[email protected]> Acked-by: Eric Dumazet <[email protected]> Cc: Mel Gorman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/file.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) --- a/fs/file.c +++ b/fs/file.c @@ -9,6 +9,7 @@ #include <linux/module.h> #include <linux/fs.h> #include <linux/mm.h> +#include <linux/mmzone.h> #include <linux/time.h> #include <linux/sched.h> #include <linux/slab.h> @@ -39,14 +40,17 @@ int sysctl_nr_open_max = 1024 * 1024; /* */ static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list); -static inline void *alloc_fdmem(unsigned int size) +static void *alloc_fdmem(unsigned int size) { - void *data; - - data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN); - if (data != NULL) - return data; - + /* + * Very large allocations can stress page reclaim, so fall back to + * vmalloc() if the allocation size will be considered "large" by the VM. + */ + if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { + void *data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN); + if (data != NULL) + return data; + } return vmalloc(size); } _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
