Andrew, On Wed, Sep 26, 2012 at 6:42 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 25 Sep 2012 22:15:38 -0300 > Ezequiel Garcia <elezegarcia@xxxxxxxxx> wrote: > >> > This patch increases util.o's text size by 238 bytes. A larger kernel >> > with a worsened cache footprint. >> > >> > And we did this to get marginally improved tracing output? This sounds >> > like a bad tradeoff to me. >> > >> >> Mmm, that's bad tradeoff indeed. >> It's certainly odd since the patch shouldn't increase the text size >> *that* much. >> Is it too much to ask that you send your kernel config and gcc version. > > x86_64 allmodconfig with CONFIG_DEBUG_INFO=n, > CONFIG_ENABLE_MUST_CHECK=n. gcc-4.4.4. > I'll try that. >> My compilation (x86 kernel in gcc 4.7.1) shows a kernel less bloated: >> >> $ readelf -s util-dup-user.o | grep dup_user >> 161: 00001c10 108 FUNC GLOBAL DEFAULT 1 memdup_user >> 169: 00001df0 159 FUNC GLOBAL DEFAULT 1 strndup_user >> $ readelf -s util.o | grep dup_user >> 161: 00001c10 108 FUNC GLOBAL DEFAULT 1 memdup_user >> 169: 00001df0 98 FUNC GLOBAL DEFAULT 1 strndup_user >> >> $ size util.o >> text data bss dec hex filename >> 18319 2077 0 20396 4fac util.o >> $ size util-dup-user.o >> text data bss dec hex filename >> 18367 2077 0 20444 4fdc util-dup-user.o >> >> Am I doing anything wrong? > > Dunno - it could be a config thing. > I'm kind of lost. The patch really shouldn't fatten the kernel this way :-( The patch was meant to improve tracing for memory tracking, which in turn would be used to reduce memory footprint. So, definitely I don't want to increase kernel text size. I'll test that kernel config and see what I can do. Thanks, Ezequiel. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>