Eric Lee / smarc-fsl-linux-kernel

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Commit e48293fd75b3aa67f43ad6e3d2ff397caa55d58b

Authored by Johannes Weiner
Committed by Linus Torvalds
1 parent 25ef0e50cc
Exists in master and in 39 other branches 8mp-imx_5.4.70_2.3.0, 8qm-imx_5.4.70_2.3.0, emb_imx_lf-5.15.y, emb_lf-6.1.y, imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, imx_4.1.15_1.0.0_ga, pitx_8mp_lf-5.10.y, rt-smarc-imx_4.1.15_1.0.0_ga, rt_linux_5.15.71, smarc-8m-android-11.0.0_2.0.0, smarc-imx6_4.14.98_2.0.0_ga, smarc-imx6_4.9.88_2.0.0_ga, smarc-imx7_4.14.98_2.0.0_ga, smarc-imx7_4.9.11_1.0.0_ga, smarc-imx7_4.9.88_2.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-imx_4.1.15_1.0.0_ga, smarc-imx_4.9.11_1.0.0_ga, smarc-imx_4.9.51_imx8m_ga, smarc-imx_4.9.88_2.0.0_ga, smarc-m6.0.1_2.1.0-ga, smarc-n7.1.2_2.0.0-ga, smarc-rel_imx_4.1.15_1.2.0_ga, smarc_8m_00d0_imx_4.14.98_2.0.0_ga, smarc_8m_imx_4.14.78_1.0.0_ga, smarc_8m_imx_4.14.98_2.0.0_ga, smarc_8m_imx_4.19.35_1.1.0, smarc_8mm_imx_4.14.78_1.0.0_ga, smarc_8mm_imx_4.14.98_2.0.0_ga, smarc_8mm_imx_4.19.35_1.1.0, smarc_8mm_imx_5.4.24_2.1.0, smarc_8mp_lf-5.10.y, smarc_8mq_imx_5.4.24_2.1.0, smarc_8mq_lf-5.10.y, smarc_imx_lf-5.15.y

mincore: do nested page table walks 

Do page table walks with the well-known nested loops we use in several
other places already.

This avoids doing full page table walks after every pte range and also
allows to handle unmapped areas bigger than one pte range in one go.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 58 additions and 17 deletions Side-by-side Diff

... ... @@ -144,6 +144,60 @@
144 144 pte_unmap_unlock(ptep - 1, ptl);
145 145 }
146 146  
  147 +static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud,
  148 + unsigned long addr, unsigned long end,
  149 + unsigned char *vec)
  150 +{
  151 + unsigned long next;
  152 + pmd_t *pmd;
  153 +
  154 + pmd = pmd_offset(pud, addr);
  155 + do {
  156 + next = pmd_addr_end(addr, end);
  157 + if (pmd_none_or_clear_bad(pmd))
  158 + mincore_unmapped_range(vma, addr, next, vec);
  159 + else
  160 + mincore_pte_range(vma, pmd, addr, next, vec);
  161 + vec += (next - addr) >> PAGE_SHIFT;
  162 + } while (pmd++, addr = next, addr != end);
  163 +}
  164 +
  165 +static void mincore_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
  166 + unsigned long addr, unsigned long end,
  167 + unsigned char *vec)
  168 +{
  169 + unsigned long next;
  170 + pud_t *pud;
  171 +
  172 + pud = pud_offset(pgd, addr);
  173 + do {
  174 + next = pud_addr_end(addr, end);
  175 + if (pud_none_or_clear_bad(pud))
  176 + mincore_unmapped_range(vma, addr, next, vec);
  177 + else
  178 + mincore_pmd_range(vma, pud, addr, next, vec);
  179 + vec += (next - addr) >> PAGE_SHIFT;
  180 + } while (pud++, addr = next, addr != end);
  181 +}
  182 +
  183 +static void mincore_page_range(struct vm_area_struct *vma,
  184 + unsigned long addr, unsigned long end,
  185 + unsigned char *vec)
  186 +{
  187 + unsigned long next;
  188 + pgd_t *pgd;
  189 +
  190 + pgd = pgd_offset(vma->vm_mm, addr);
  191 + do {
  192 + next = pgd_addr_end(addr, end);
  193 + if (pgd_none_or_clear_bad(pgd))
  194 + mincore_unmapped_range(vma, addr, next, vec);
  195 + else
  196 + mincore_pud_range(vma, pgd, addr, next, vec);
  197 + vec += (next - addr) >> PAGE_SHIFT;
  198 + } while (pgd++, addr = next, addr != end);
  199 +}
  200 +
147 201 /*
148 202 * Do a chunk of "sys_mincore()". We've already checked
149 203 * all the arguments, we hold the mmap semaphore: we should
... ... @@ -151,9 +205,6 @@
151 205 */
152 206 static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *vec)
153 207 {
154   - pgd_t *pgd;
155   - pud_t *pud;
156   - pmd_t *pmd;
157 208 struct vm_area_struct *vma;
158 209 unsigned long end;
159 210  
160 211  
... ... @@ -170,21 +221,11 @@
170 221  
171 222 end = pmd_addr_end(addr, end);
172 223  
173   - pgd = pgd_offset(vma->vm_mm, addr);
174   - if (pgd_none_or_clear_bad(pgd))
175   - goto none_mapped;
176   - pud = pud_offset(pgd, addr);
177   - if (pud_none_or_clear_bad(pud))
178   - goto none_mapped;
179   - pmd = pmd_offset(pud, addr);
180   - if (pmd_none_or_clear_bad(pmd))
181   - goto none_mapped;
  224 + if (is_vm_hugetlb_page(vma))
  225 + mincore_hugetlb_page_range(vma, addr, end, vec);
  226 + else
  227 + mincore_page_range(vma, addr, end, vec);
182 228  
183   - mincore_pte_range(vma, pmd, addr, end, vec);
184   - return (end - addr) >> PAGE_SHIFT;
185   -
186   -none_mapped:
187   - mincore_unmapped_range(vma, addr, end, vec);
188 229 return (end - addr) >> PAGE_SHIFT;
189 230 }
190 231