Hi, kstrdup if often used to duplicate strings where neither source neither destination will be ever modified. In such case we can just reuse the source instead of duplicating it. The problem is that we must be sure that the source is non-modifiable and its life-time is long enough. I suspect the good candidates for such strings are strings located in kernel .rodata section, they cannot be modifed because the section is read-only and their life-time is equal to kernel life-time. This small patchset proposes alternative version of kstrdup - kstrdup_const, which returns source string if it is located in .rodata otherwise it fallbacks to kstrdup. To verify if the source is in .rodata function checks if the address is between sentinels __start_rodata, __end_rodata. I guess it should work with all architectures. The main patch is accompanied by four patches constifying kstrdup for cases where situtation described above happens frequently. As I have tested the patchset on mobile platform (exynos4210-trats) it saves 3272 string allocations. Since minimal allocation is 32 or 64 bytes depending on Kconfig options the patchset saves respectively about 100KB or 200KB of memory. The patchset is based on 3.19-rc4. This patchset have been already sent to the list as RFC. Current version have following changes: - added missing export, - added kerneldocs, - constified kstrdup in VFS devname allocation. Regards Andrzej Andrzej Hajda (5): mm/util: add kstrdup_const kernfs: convert node name allocation to kstrdup_const clk: convert clock name allocations to kstrdup_const mm/slab: convert cache name allocations to kstrdup_const fs/namespace: convert devname allocation to kstrdup_const drivers/clk/clk.c | 12 ++++++------ fs/kernfs/dir.c | 12 ++++++------ fs/namespace.c | 6 +++--- include/linux/string.h | 3 +++ mm/slab_common.c | 6 +++--- mm/util.c | 38 ++++++++++++++++++++++++++++++++++++++ 6 files changed, 59 insertions(+), 18 deletions(-) -- 1.9.1 -- 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>