diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2013-10-31 13:55:45 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-01-03 04:33:16 +0000 |
| commit | 224a07b498254bf980d8c797064e00ec950e56ef (patch) | |
| tree | 021ca65b3147f086e856f669d1ca0eeeddc38799 | |
| parent | f38808475d3ef744bc6e2610e33fb4c92dc85654 (diff) | |
dm: allocate buffer for messages with small number of arguments using GFP_NOIO
commit f36afb3957353d2529cb2b00f78fdccd14fc5e9c upstream.
dm-mpath and dm-thin must process messages even if some device is
suspended, so we allocate argv buffer with GFP_NOIO. These messages have
a small fixed number of arguments.
On the other hand, dm-switch needs to process bulk data using messages
so excessive use of GFP_NOIO could cause trouble.
The patch also lowers the default number of arguments from 64 to 8, so
that there is smaller load on GFP_NOIO allocations.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/md/dm-table.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 52848ab56c9..72c0dfb301f 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -581,14 +581,28 @@ static int adjoin(struct dm_table *table, struct dm_target *ti) /* * Used to dynamically allocate the arg array. + * + * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must + * process messages even if some device is suspended. These messages have a + * small fixed number of arguments. + * + * On the other hand, dm-switch needs to process bulk data using messages and + * excessive use of GFP_NOIO could cause trouble. */ static char **realloc_argv(unsigned *array_size, char **old_argv) { char **argv; unsigned new_size; + gfp_t gfp; - new_size = *array_size ? *array_size * 2 : 64; - argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); + if (*array_size) { + new_size = *array_size * 2; + gfp = GFP_KERNEL; + } else { + new_size = 8; + gfp = GFP_NOIO; + } + argv = kmalloc(new_size * sizeof(*argv), gfp); if (argv) { memcpy(argv, old_argv, *array_size * sizeof(*argv)); *array_size = new_size; |