2:19 a.m.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: cd557f1c605fc5a2c0eb0b540610f50dc67dd849
commit: dbee97d1f49a2f2f1f5c26bf15151cc998572e89 [2950/3150] mm/mremap: use
pmd/pud_poplulate to update page table entries
config: i386-randconfig-r006-20210517 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
#
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi...
git remote add linux-next
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git fetch --no-tags linux-next master
git checkout dbee97d1f49a2f2f1f5c26bf15151cc998572e89
# save the attached .config to linux build tree
make W=1 W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
All warnings (new ones prefixed by >>):
mm/mremap.c: In function 'move_normal_pud':
> mm/mremap.c:285:8: warning: variable 'pud' set but not
used [-Wunused-but-set-variable]
285 | pud_t pud;
| ^~~
vim +/pud +285 mm/mremap.c
2c91bd4a4e2e53 Joel Fernandes (Google 2019-01-03 278)
c49dd340180260 Kalesh Singh 2020-12-14 279 #ifdef CONFIG_HAVE_MOVE_PUD
c49dd340180260 Kalesh Singh 2020-12-14 280 static bool move_normal_pud(struct
vm_area_struct *vma, unsigned long old_addr,
c49dd340180260 Kalesh Singh 2020-12-14 281 unsigned long new_addr, pud_t
*old_pud, pud_t *new_pud)
c49dd340180260 Kalesh Singh 2020-12-14 282 {
c49dd340180260 Kalesh Singh 2020-12-14 283 spinlock_t *old_ptl, *new_ptl;
c49dd340180260 Kalesh Singh 2020-12-14 284 struct mm_struct *mm =
vma->vm_mm;
c49dd340180260 Kalesh Singh 2020-12-14 @285 pud_t pud;
c49dd340180260 Kalesh Singh 2020-12-14 286
c49dd340180260 Kalesh Singh 2020-12-14 287 /*
c49dd340180260 Kalesh Singh 2020-12-14 288 * The destination pud
shouldn't be established, free_pgtables()
c49dd340180260 Kalesh Singh 2020-12-14 289 * should have released it.
c49dd340180260 Kalesh Singh 2020-12-14 290 */
c49dd340180260 Kalesh Singh 2020-12-14 291 if
(WARN_ON_ONCE(!pud_none(*new_pud)))
c49dd340180260 Kalesh Singh 2020-12-14 292 return false;
c49dd340180260 Kalesh Singh 2020-12-14 293
c49dd340180260 Kalesh Singh 2020-12-14 294 /*
c49dd340180260 Kalesh Singh 2020-12-14 295 * We don't have to worry
about the ordering of src and dst
c49dd340180260 Kalesh Singh 2020-12-14 296 * ptlocks because exclusive
mmap_lock prevents deadlock.
c49dd340180260 Kalesh Singh 2020-12-14 297 */
c49dd340180260 Kalesh Singh 2020-12-14 298 old_ptl = pud_lock(vma->vm_mm,
old_pud);
c49dd340180260 Kalesh Singh 2020-12-14 299 new_ptl = pud_lockptr(mm,
new_pud);
c49dd340180260 Kalesh Singh 2020-12-14 300 if (new_ptl != old_ptl)
c49dd340180260 Kalesh Singh 2020-12-14 301 spin_lock_nested(new_ptl,
SINGLE_DEPTH_NESTING);
c49dd340180260 Kalesh Singh 2020-12-14 302
c49dd340180260 Kalesh Singh 2020-12-14 303 /* Clear the pud */
c49dd340180260 Kalesh Singh 2020-12-14 304 pud = *old_pud;
c49dd340180260 Kalesh Singh 2020-12-14 305 pud_clear(old_pud);
c49dd340180260 Kalesh Singh 2020-12-14 306
c49dd340180260 Kalesh Singh 2020-12-14 307 VM_BUG_ON(!pud_none(*new_pud));
c49dd340180260 Kalesh Singh 2020-12-14 308
dbee97d1f49a2f Aneesh Kumar K.V 2021-05-14 309 pud_populate(mm, new_pud, (pmd_t
*)pud_page_vaddr(pud));
c49dd340180260 Kalesh Singh 2020-12-14 310 flush_tlb_range(vma, old_addr,
old_addr + PUD_SIZE);
c49dd340180260 Kalesh Singh 2020-12-14 311 if (new_ptl != old_ptl)
c49dd340180260 Kalesh Singh 2020-12-14 312 spin_unlock(new_ptl);
c49dd340180260 Kalesh Singh 2020-12-14 313 spin_unlock(old_ptl);
c49dd340180260 Kalesh Singh 2020-12-14 314
c49dd340180260 Kalesh Singh 2020-12-14 315 return true;
c49dd340180260 Kalesh Singh 2020-12-14 316 }
c49dd340180260 Kalesh Singh 2020-12-14 317 #else
c49dd340180260 Kalesh Singh 2020-12-14 318 static inline bool
move_normal_pud(struct vm_area_struct *vma,
c49dd340180260 Kalesh Singh 2020-12-14 319 unsigned long old_addr, unsigned
long new_addr, pud_t *old_pud,
c49dd340180260 Kalesh Singh 2020-12-14 320 pud_t *new_pud)
c49dd340180260 Kalesh Singh 2020-12-14 321 {
c49dd340180260 Kalesh Singh 2020-12-14 322 return false;
c49dd340180260 Kalesh Singh 2020-12-14 323 }
c49dd340180260 Kalesh Singh 2020-12-14 324 #endif
c49dd340180260 Kalesh Singh 2020-12-14 325
:::::: The code at line 285 was first introduced by commit
:::::: c49dd340180260c6239e453263a9a244da9a7c85 mm: speedup mremap on 1GB or larger
regions
:::::: TO: Kalesh Singh <kaleshsingh(a)google.com>
:::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org>
---
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