Dear Christoph,
Am 12.05.22 um 08:27 schrieb Christoph Hellwig:
On Thu, May 12, 2022 at 08:25:28AM +0200, Paul Menzel wrote:
Am 12.05.22 um 08:19 schrieb Christoph Hellwig:
Use the %pg format specifier to save on stack consuption and code size.
consu*m*ption
Did you do any measurements?
Each BDEVNAME_SIZE array consumes 32 bytes on the stack, and they are
gone now without any additional stack usage elsewhere.
Understood.
For comparing the code size, out of curiosity, I built `drivers/md` from
md-next, commit 74fe94569da7 (md: protect md_unregister_thread from
reentrancy), without and with your patch with gcc 11.1.0, and got:
```
$ diff -u <(cd drivers/md-before/ && du -a | sort -k2) <(cd drivers/md/
&& du -a | sort -k2)
--- /dev/fd/63 2022-05-12 09:51:23.354107016 +0200
+++ /dev/fd/62 2022-05-12 09:51:23.355107064 +0200
@@ -1,4 +1,4 @@
-11064 .
+11052 .
4 ./.built-in.a.cmd
48 ./.dm-bio-prison-v1.o.cmd
20 ./.dm-bio-prison-v1.o.d
@@ -287,7 +287,7 @@
24 ./md-multipath.o
260 ./md.c
28 ./md.h
-308 ./md.o
+304 ./md.o
4 ./modules.order
1380 ./persistent-data
48 ./persistent-data/.dm-array.o.cmd
@@ -356,7 +356,7 @@
148 ./raid10.c
8 ./raid10.h
4 ./raid10.mod
-108 ./raid10.o
+104 ./raid10.o
88 ./raid5-cache.c
76 ./raid5-cache.o
8 ./raid5-log.h
@@ -364,4 +364,4 @@
48 ./raid5-ppl.o
252 ./raid5.c
32 ./raid5.h
-212 ./raid5.o
+208 ./raid5.o
```
Kind regards,
Paul
