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  • Committer: Bazaar Package Importer
  • Author(s): Paolo Pisati
  • Date: 2011-06-29 15:23:51 UTC
  • mfrom: (26.1.1 natty-proposed)
  • Revision ID: james.westby@ubuntu.com-20110629152351-xs96tm303d95rpbk
Tags: 3.0.0-1200.2
* Rebased against 3.0.0-6.7
* BSP from TI based on 3.0.0

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mm/ksm.c
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#include <linux/ksm.h>
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#include <linux/hash.h>
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#include <linux/freezer.h>
 
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#include <linux/oom.h>
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#include <asm/tlbflush.h>
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#include "internal.h"
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        return rmap_item->address & STABLE_FLAG;
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}
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static void hold_anon_vma(struct rmap_item *rmap_item,
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                          struct anon_vma *anon_vma)
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{
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        rmap_item->anon_vma = anon_vma;
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        get_anon_vma(anon_vma);
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}
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static void ksm_drop_anon_vma(struct rmap_item *rmap_item)
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{
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        struct anon_vma *anon_vma = rmap_item->anon_vma;
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        drop_anon_vma(anon_vma);
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}
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/*
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 * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's
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 * page tables after it has passed through ksm_exit() - which, if necessary,
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         * It is not an accident that whenever we want to break COW
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         * to undo, we also need to drop a reference to the anon_vma.
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         */
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        ksm_drop_anon_vma(rmap_item);
 
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        put_anon_vma(rmap_item->anon_vma);
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        down_read(&mm->mmap_sem);
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        if (ksm_test_exit(mm))
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                        ksm_pages_sharing--;
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                else
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                        ksm_pages_shared--;
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                ksm_drop_anon_vma(rmap_item);
 
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                put_anon_vma(rmap_item->anon_vma);
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                rmap_item->address &= PAGE_MASK;
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                cond_resched();
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        }
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                else
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                        ksm_pages_shared--;
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                ksm_drop_anon_vma(rmap_item);
 
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                put_anon_vma(rmap_item->anon_vma);
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                rmap_item->address &= PAGE_MASK;
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        } else if (rmap_item->address & UNSTABLE_FLAG) {
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                swapped = PageSwapCache(page);
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                flush_cache_page(vma, addr, page_to_pfn(page));
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                /*
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                 * Ok this is tricky, when get_user_pages_fast() run it doesnt
 
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                 * Ok this is tricky, when get_user_pages_fast() run it doesn't
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                 * take any lock, therefore the check that we are going to make
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                 * with the pagecount against the mapcount is racey and
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                 * O_DIRECT can happen right after the check.
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                goto out;
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        /* Must get reference to anon_vma while still holding mmap_sem */
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        hold_anon_vma(rmap_item, vma->anon_vma);
 
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        rmap_item->anon_vma = vma->anon_vma;
 
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        get_anon_vma(vma->anon_vma);
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out:
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        up_read(&mm->mmap_sem);
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        return err;
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                slot = list_entry(slot->mm_list.next, struct mm_slot, mm_list);
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                ksm_scan.mm_slot = slot;
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                spin_unlock(&ksm_mmlist_lock);
 
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                /*
 
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                 * Although we tested list_empty() above, a racing __ksm_exit
 
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                 * of the last mm on the list may have removed it since then.
 
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                 */
 
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                if (slot == &ksm_mm_head)
 
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                        return NULL;
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next_mm:
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                ksm_scan.address = 0;
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                ksm_scan.rmap_list = &slot->rmap_list;
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        if (ksm_run != flags) {
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                ksm_run = flags;
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                if (flags & KSM_RUN_UNMERGE) {
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                        current->flags |= PF_OOM_ORIGIN;
 
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                        int oom_score_adj;
 
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                        oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX);
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                        err = unmerge_and_remove_all_rmap_items();
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                        current->flags &= ~PF_OOM_ORIGIN;
 
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                        test_set_oom_score_adj(oom_score_adj);
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                        if (err) {
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                                ksm_run = KSM_RUN_STOP;
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                                count = err;