Fix slabinfo display format, if a structure length > 17, the information display like:
[root@localhost ~]# cat /proc/slabinfo
flow_cache 0 0 80 48 1 : tunables 120 60 8 : slabdata 0 0 0
cfq_io_context 40 112 68 56 1 : tunables 120 60 8 : slabdata 2 2 0
cfq_queue 30 52 152 26 1 : tunables 120 60 8 : slabdata 2 2 0
bsg_cmd 0 0 284 14 1 : tunables 54 27 8 : slabdata 0 0 0
mqueue_inode_cache 1 7 576 7 1 : tunables 54 27 8 : slabdata 1 1 0
isofs_inode_cache 0 0 380 10 1 : tunables 54 27 8 : slabdata 0 0 0
hugetlbfs_inode_cache 1 11 352 11 1 : tunables 54 27 8 : slabdata 1 1 0
ext2_inode_cache 0 0 496 8 1 : tunables 54 27 8 : slabdata 0 0 0
ext2_xattr 0 0 48 78 1 : tunables 120 60 8 : slabdata 0 0 0
dquot 0 0 192 20 1 : tunables 120 60 8 : slabdata 0 0 0
kioctx 0 0 192 20 1 : tunables 120 60 8 : slabdata 0 0 0
kiocb 0 0 128 30 1 : tunables 120 60 8 : slabdata 0 0 0
Signed-off-by: Zhitong Wang <[email protected]>
---
mm/slab.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c
index e49f8f4..3bcba98 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4181,7 +4181,7 @@ static void print_slabinfo_header(struct seq_file *m)
#else
seq_puts(m, "slabinfo - version: 2.1\n");
#endif
- seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
+ seq_puts(m, "# name\t\t\t<active_objs> <num_objs> <objsize> "
"<objperslab> <pagesperslab>");
seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
@@ -4271,7 +4271,7 @@ static int s_show(struct seq_file *m, void *p)
if (error)
printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
- seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
+ seq_printf(m, "%-27s %6lu %6lu %6u %4u %4d",
name, active_objs, num_objs, cachep->buffer_size,
cachep->num, (1 << cachep->gfporder));
seq_printf(m, " : tunables %4u %4u %4u",
--
1.6.5.3
On Thu, 17 Jun 2010, [email protected] wrote:
> @@ -4271,7 +4271,7 @@ static int s_show(struct seq_file *m, void *p)
> if (error)
> printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
>
> - seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
> + seq_printf(m, "%-27s %6lu %6lu %6u %4u %4d",
> name, active_objs, num_objs, cachep->buffer_size,
> cachep->num, (1 << cachep->gfporder));
> seq_printf(m, " : tunables %4u %4u %4u",
This one may break user space tools that have assumptions about the length
of the field. Or do tools not make that assumption?
On Thu, Jun 17, 2010 at 9:45 PM, Christoph Lameter
<[email protected]> wrote:
> On Thu, 17 Jun 2010, [email protected] wrote:
> This one may break user space tools that have assumptions about the length
> of the field. Or do tools not make that assumption?
>
User space tools usually use sscanf() to extract this field like:
sscanf(buff, "%s %d", name, &num);
If %-27s can break some user space tools that have assumptions about
the length of the field, the orig %-17s can also break it.
The longest name inotify_event_private_data is 26 bytes in 2.6.34-rc2,
the tools still can't extract it.
On 6/17/10 5:10 PM, wzt wzt wrote:
> On Thu, Jun 17, 2010 at 9:45 PM, Christoph Lameter
> <[email protected]> wrote:
>> On Thu, 17 Jun 2010, [email protected] wrote:
>
>> This one may break user space tools that have assumptions about the length
>> of the field. Or do tools not make that assumption?
>
> User space tools usually use sscanf() to extract this field like:
> sscanf(buff, "%s %d", name,&num);
> If %-27s can break some user space tools that have assumptions about
> the length of the field, the orig %-17s can also break it.
> The longest name inotify_event_private_data is 26 bytes in 2.6.34-rc2,
> the tools still can't extract it.
NAK. It's an ABI so the risks of this format cleanup outweight the benefits.
Pekka