lkml.org 
[lkml]   [2012]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [PATCH v4 1/3] memcg: clean up existing move charge code
    On Mon, 12 Mar 2012 18:30:54 -0400
    Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> wrote:

    > We'll introduce the thp variant of move charge code in later patches,
    > but before doing that let's start with refactoring existing code.
    > Here we replace lengthy function name is_target_pte_for_mc() with
    > shorter one in order to avoid ugly line breaks.
    > And for better readability, we explicitly use MC_TARGET_* instead of
    > simply using integers.
    >
    > Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>

    Thanks.

    Seems ok to me.
    Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.futjisu.com>

    Hmm. some nitpicks.

    > ---
    > mm/memcontrol.c | 20 ++++++++++----------
    > 1 files changed, 10 insertions(+), 10 deletions(-)
    >
    > diff --git linux-next-20120307.orig/mm/memcontrol.c linux-next-20120307/mm/memcontrol.c
    > index a288855..3d16618 100644
    > --- linux-next-20120307.orig/mm/memcontrol.c
    > +++ linux-next-20120307/mm/memcontrol.c
    > @@ -5069,7 +5069,7 @@ one_by_one:
    > }
    >
    > /**
    > - * is_target_pte_for_mc - check a pte whether it is valid for move charge
    > + * get_mctgt_type - get target type of moving charge
    > * @vma: the vma the pte to be checked belongs
    > * @addr: the address corresponding to the pte to be checked
    > * @ptent: the pte to be checked
    > @@ -5092,7 +5092,7 @@ union mc_target {
    > };
    >
    > enum mc_target_type {
    > - MC_TARGET_NONE, /* not used */
    > + MC_TARGET_NONE,

    How about

    MC_TARGET_NONE = 0,

    Becasue you use
    if (get_mctgt_type())
    later.



    > MC_TARGET_PAGE,
    > MC_TARGET_SWAP,
    > };
    > @@ -5173,12 +5173,12 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
    > return page;
    > }
    >
    > -static int is_target_pte_for_mc(struct vm_area_struct *vma,
    > +static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
    > unsigned long addr, pte_t ptent, union mc_target *target)

    I admit old name is too long. But...Hm...get_mctgt_type()...how about

    move_charge_type() or
    mctgt_type() or
    mc_type() ?

    I don't have good sense of naming ;(

    > {
    > struct page *page = NULL;
    > struct page_cgroup *pc;
    > - int ret = 0;
    > + enum mc_target_type ret = MC_TARGET_NONE;
    > swp_entry_t ent = { .val = 0 };
    >
    > if (pte_present(ptent))
    > @@ -5189,7 +5189,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
    > page = mc_handle_file_pte(vma, addr, ptent, &ent);
    >
    > if (!page && !ent.val)
    > - return 0;
    > + return ret;
    > if (page) {
    > pc = lookup_page_cgroup(page);
    > /*
    > @@ -5206,7 +5206,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
    > put_page(page);
    > }
    > /* There is a swap entry and a page doesn't exist or isn't charged */
    > - if (ent.val && !ret &&
    > + if (ent.val && ret != MC_TARGET_NONE &&

    If you do MC_TARGET_NONE = 0 in above, using !ret seems ok to me.

    > css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
    > ret = MC_TARGET_SWAP;
    > if (target)
    > @@ -5227,7 +5227,7 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
    >
    > pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
    > for (; addr != end; pte++, addr += PAGE_SIZE)
    > - if (is_target_pte_for_mc(vma, addr, *pte, NULL))
    > + if (get_mctgt_type(vma, addr, *pte, NULL))
    > mc.precharge++; /* increment precharge temporarily */
    > pte_unmap_unlock(pte - 1, ptl);
    > cond_resched();
    > @@ -5397,8 +5397,8 @@ retry:
    > if (!mc.precharge)
    > break;
    >
    > - type = is_target_pte_for_mc(vma, addr, ptent, &target);
    > - switch (type) {
    > + target_type = get_mctgt_type(vma, addr, ptent, &target);
    > + switch (target_type) {

    It 'target_type' is unused later

    switch(get_mctgt_type(vma, addr, ptent, &target))

    is ok ?

    Thanks,
    -Kame

    > case MC_TARGET_PAGE:
    > page = target.page;
    > if (isolate_lru_page(page))
    > @@ -5411,7 +5411,7 @@ retry:
    > mc.moved_charge++;
    > }
    > putback_lru_page(page);
    > -put: /* is_target_pte_for_mc() gets the page */
    > +put: /* get_mctgt_type() gets the page */
    > put_page(page);
    > break;
    > case MC_TARGET_SWAP:
    > --
    > 1.7.7.6
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at http://www.tux.org/lkml/



    \
     
     \ /
      Last update: 2012-03-13 06:49    [W:0.061 / U:66.568 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site