Hi Joonsoo, On Fri, Dec 7, 2012 at 12:09 AM, Joonsoo Kim <js1304 at gmail.com> wrote: > This patchset remove vm_struct list management after initializing vmalloc. > Adding and removing an entry to vmlist is linear time complexity, so > it is inefficient. If we maintain this list, overall time complexity of > adding and removing area to vmalloc space is O(N), although we use > rbtree for finding vacant place and it's time complexity is just O(logN). > > And vmlist and vmlist_lock is used many places of outside of vmalloc.c. > It is preferable that we hide this raw data structure and provide > well-defined function for supporting them, because it makes that they > cannot mistake when manipulating theses structure and it makes us easily > maintain vmalloc layer. > > I'm not sure that "7/8: makes vmlist only for kexec" is fine. > Because it is related to userspace program. > As far as I know, makedumpfile use kexec's output information and it only > need first address of vmalloc layer. So my implementation reflect this > fact, but I'm not sure. And now, I don't fully test this patchset. > Basic operation work well, but I don't test kexec. So I send this > patchset with 'RFC'. > > Please let me know what I am missing. > Nice work! I also thought about this several weeks ago but I think the efficiency may be a problem. As you know two locks(vmap_area_lock and vmlist_lock) are used currently so that some work may be done in parallel(not proved). If removed vmlist, i'm afraid vmap_area_lock will become a bottleneck which will reduce the efficiency. > This series based on v3.7-rc7 and on top of submitted patchset for ARM. > 'introduce static_vm for ARM-specific static mapped area' > https://lkml.org/lkml/2012/11/27/356 > But, running properly on x86 without ARM patchset. > > Joonsoo Kim (8): > mm, vmalloc: change iterating a vmlist to find_vm_area() > mm, vmalloc: move get_vmalloc_info() to vmalloc.c > mm, vmalloc: protect va->vm by vmap_area_lock > mm, vmalloc: iterate vmap_area_list, instead of vmlist in > vread/vwrite() > mm, vmalloc: iterate vmap_area_list in get_vmalloc_info() > mm, vmalloc: iterate vmap_area_list, instead of vmlist, in > vmallocinfo() > mm, vmalloc: makes vmlist only for kexec > mm, vmalloc: remove list management operation after initializing > vmalloc > > arch/tile/mm/pgtable.c | 7 +- > arch/unicore32/mm/ioremap.c | 17 +-- > arch/x86/mm/ioremap.c | 7 +- > fs/proc/Makefile | 2 +- > fs/proc/internal.h | 18 --- > fs/proc/meminfo.c | 1 + > fs/proc/mmu.c | 60 ---------- > include/linux/vmalloc.h | 19 +++- > mm/vmalloc.c | 258 +++++++++++++++++++++++++++++-------------- > 9 files changed, 204 insertions(+), 185 deletions(-) > delete mode 100644 fs/proc/mmu.c > > -- > 1.7.9.5 > -- Regards, --Bob
