[PATCH v2] arm64: mm: fix linear mapping mem access performance degradation
kernel test robot
lkp at intel.com
Thu Jun 30 13:15:13 PDT 2022
Hi Guanghui,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on v5.19-rc4]
[also build test WARNING on linus/master next-20220630]
[cannot apply to arm64/for-next/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Guanghui-Feng/arm64-mm-fix-linear-mapping-mem-access-performance-degradation/20220630-163924
base: 03c765b0e3b4cb5063276b086c76f7a612856a9a
config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20220701/202207010409.ajCVDXYO-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/168f0d56f0a26c4f7a9470d6f1c398b4e1c1b5b9
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Guanghui-Feng/arm64-mm-fix-linear-mapping-mem-access-performance-degradation/20220630-163924
git checkout 168f0d56f0a26c4f7a9470d6f1c398b4e1c1b5b9
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/mm/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp at intel.com>
All warnings (new ones prefixed by >>):
arch/arm64/mm/mmu.c: In function 'alloc_init_pud':
>> arch/arm64/mm/mmu.c:426:35: warning: suggest braces around empty body in an 'if' statement [-Wempty-body]
426 | pud_clear_fixmap();
| ^
vim +/if +426 arch/arm64/mm/mmu.c
d27cfa1fc823d3 Ard Biesheuvel 2017-03-09 333
20a004e7b017cc Will Deacon 2018-02-15 334 static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
da141706aea52c Laura Abbott 2015-01-21 335 phys_addr_t phys, pgprot_t prot,
90292aca9854a2 Yu Zhao 2019-03-11 336 phys_addr_t (*pgtable_alloc)(int),
c0951366d4b7e0 Ard Biesheuvel 2017-03-09 337 int flags)
c1cc1552616d0f Catalin Marinas 2012-03-05 338 {
168f0d56f0a26c Guanghui Feng 2022-06-30 339 phys_addr_t map_offset;
c1cc1552616d0f Catalin Marinas 2012-03-05 340 unsigned long next;
168f0d56f0a26c Guanghui Feng 2022-06-30 341 pudval_t pudval;
20a004e7b017cc Will Deacon 2018-02-15 342 pud_t *pudp;
e9f6376858b979 Mike Rapoport 2020-06-04 343 p4d_t *p4dp = p4d_offset(pgdp, addr);
e9f6376858b979 Mike Rapoport 2020-06-04 344 p4d_t p4d = READ_ONCE(*p4dp);
c1cc1552616d0f Catalin Marinas 2012-03-05 345
e9f6376858b979 Mike Rapoport 2020-06-04 346 if (p4d_none(p4d)) {
87143f404f338d Ard Biesheuvel 2021-03-10 347 p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN;
132233a759580f Laura Abbott 2016-02-05 348 phys_addr_t pud_phys;
87143f404f338d Ard Biesheuvel 2021-03-10 349
87143f404f338d Ard Biesheuvel 2021-03-10 350 if (flags & NO_EXEC_MAPPINGS)
87143f404f338d Ard Biesheuvel 2021-03-10 351 p4dval |= P4D_TABLE_PXN;
132233a759580f Laura Abbott 2016-02-05 352 BUG_ON(!pgtable_alloc);
90292aca9854a2 Yu Zhao 2019-03-11 353 pud_phys = pgtable_alloc(PUD_SHIFT);
87143f404f338d Ard Biesheuvel 2021-03-10 354 __p4d_populate(p4dp, pud_phys, p4dval);
e9f6376858b979 Mike Rapoport 2020-06-04 355 p4d = READ_ONCE(*p4dp);
c79b954bf6c006 Jungseok Lee 2014-05-12 356 }
e9f6376858b979 Mike Rapoport 2020-06-04 357 BUG_ON(p4d_bad(p4d));
c79b954bf6c006 Jungseok Lee 2014-05-12 358
ee017ee353506f Jianyong Wu 2022-02-01 359 /*
ee017ee353506f Jianyong Wu 2022-02-01 360 * No need for locking during early boot. And it doesn't work as
ee017ee353506f Jianyong Wu 2022-02-01 361 * expected with KASLR enabled.
ee017ee353506f Jianyong Wu 2022-02-01 362 */
ee017ee353506f Jianyong Wu 2022-02-01 363 if (system_state != SYSTEM_BOOTING)
ee017ee353506f Jianyong Wu 2022-02-01 364 mutex_lock(&fixmap_lock);
168f0d56f0a26c Guanghui Feng 2022-06-30 365
168f0d56f0a26c Guanghui Feng 2022-06-30 366 pudp = (flags & NO_SEC_REMAPPINGS) ? pud_offset(p4dp, addr) :
168f0d56f0a26c Guanghui Feng 2022-06-30 367 pud_set_fixmap_offset(p4dp, addr);
c1cc1552616d0f Catalin Marinas 2012-03-05 368 do {
20a004e7b017cc Will Deacon 2018-02-15 369 pud_t old_pud = READ_ONCE(*pudp);
c1cc1552616d0f Catalin Marinas 2012-03-05 370 next = pud_addr_end(addr, end);
206a2a73a62d37 Steve Capper 2014-05-06 371
168f0d56f0a26c Guanghui Feng 2022-06-30 372 if (flags & NO_SEC_REMAPPINGS) {
168f0d56f0a26c Guanghui Feng 2022-06-30 373 if (!pud_none(*pudp) && pud_sect(*pudp)) {
168f0d56f0a26c Guanghui Feng 2022-06-30 374 phys_addr_t pmd_phys = pgtable_alloc(PMD_SHIFT);
168f0d56f0a26c Guanghui Feng 2022-06-30 375 pud_clear(pudp);
168f0d56f0a26c Guanghui Feng 2022-06-30 376 pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN;
168f0d56f0a26c Guanghui Feng 2022-06-30 377 if (flags & NO_EXEC_MAPPINGS)
168f0d56f0a26c Guanghui Feng 2022-06-30 378 pudval |= PUD_TABLE_PXN;
168f0d56f0a26c Guanghui Feng 2022-06-30 379
168f0d56f0a26c Guanghui Feng 2022-06-30 380 __pud_populate(pudp, pmd_phys, pudval);
168f0d56f0a26c Guanghui Feng 2022-06-30 381 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
168f0d56f0a26c Guanghui Feng 2022-06-30 382
168f0d56f0a26c Guanghui Feng 2022-06-30 383 map_offset = addr - (addr & PUD_MASK);
168f0d56f0a26c Guanghui Feng 2022-06-30 384 if (map_offset)
168f0d56f0a26c Guanghui Feng 2022-06-30 385 alloc_init_cont_pmd(pudp, addr & PUD_MASK,
168f0d56f0a26c Guanghui Feng 2022-06-30 386 addr, phys - map_offset,
168f0d56f0a26c Guanghui Feng 2022-06-30 387 prot, pgtable_alloc,
168f0d56f0a26c Guanghui Feng 2022-06-30 388 flags & (~NO_SEC_REMAPPINGS));
168f0d56f0a26c Guanghui Feng 2022-06-30 389
168f0d56f0a26c Guanghui Feng 2022-06-30 390 if (next < (addr & PUD_MASK) + PUD_SIZE)
168f0d56f0a26c Guanghui Feng 2022-06-30 391 alloc_init_cont_pmd(pudp, next,
168f0d56f0a26c Guanghui Feng 2022-06-30 392 (addr & PUD_MASK) +
168f0d56f0a26c Guanghui Feng 2022-06-30 393 PUD_SIZE,
168f0d56f0a26c Guanghui Feng 2022-06-30 394 next - addr + phys,
168f0d56f0a26c Guanghui Feng 2022-06-30 395 prot, pgtable_alloc,
168f0d56f0a26c Guanghui Feng 2022-06-30 396 flags & (~NO_SEC_REMAPPINGS));
168f0d56f0a26c Guanghui Feng 2022-06-30 397 }
168f0d56f0a26c Guanghui Feng 2022-06-30 398 alloc_init_cont_pmd(pudp, addr, next, phys, prot,
168f0d56f0a26c Guanghui Feng 2022-06-30 399 pgtable_alloc, flags);
168f0d56f0a26c Guanghui Feng 2022-06-30 400 }
206a2a73a62d37 Steve Capper 2014-05-06 401 /*
206a2a73a62d37 Steve Capper 2014-05-06 402 * For 4K granule only, attempt to put down a 1GB block
206a2a73a62d37 Steve Capper 2014-05-06 403 */
168f0d56f0a26c Guanghui Feng 2022-06-30 404 else if (pud_sect_supported() &&
1310222c276b79 Anshuman Khandual 2022-02-16 405 ((addr | next | phys) & ~PUD_MASK) == 0 &&
c0951366d4b7e0 Ard Biesheuvel 2017-03-09 406 (flags & NO_BLOCK_MAPPINGS) == 0) {
20a004e7b017cc Will Deacon 2018-02-15 407 pud_set_huge(pudp, phys, prot);
206a2a73a62d37 Steve Capper 2014-05-06 408
206a2a73a62d37 Steve Capper 2014-05-06 409 /*
e98216b52176ba Ard Biesheuvel 2016-10-21 410 * After the PUD entry has been populated once, we
e98216b52176ba Ard Biesheuvel 2016-10-21 411 * only allow updates to the permission attributes.
206a2a73a62d37 Steve Capper 2014-05-06 412 */
e98216b52176ba Ard Biesheuvel 2016-10-21 413 BUG_ON(!pgattr_change_is_safe(pud_val(old_pud),
20a004e7b017cc Will Deacon 2018-02-15 414 READ_ONCE(pud_val(*pudp))));
206a2a73a62d37 Steve Capper 2014-05-06 415 } else {
20a004e7b017cc Will Deacon 2018-02-15 416 alloc_init_cont_pmd(pudp, addr, next, phys, prot,
c0951366d4b7e0 Ard Biesheuvel 2017-03-09 417 pgtable_alloc, flags);
e98216b52176ba Ard Biesheuvel 2016-10-21 418
e98216b52176ba Ard Biesheuvel 2016-10-21 419 BUG_ON(pud_val(old_pud) != 0 &&
20a004e7b017cc Will Deacon 2018-02-15 420 pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
206a2a73a62d37 Steve Capper 2014-05-06 421 }
c1cc1552616d0f Catalin Marinas 2012-03-05 422 phys += next - addr;
20a004e7b017cc Will Deacon 2018-02-15 423 } while (pudp++, addr = next, addr != end);
f4710445458c0a Mark Rutland 2016-01-25 424
168f0d56f0a26c Guanghui Feng 2022-06-30 425 if (!(flags & NO_SEC_REMAPPINGS))
f4710445458c0a Mark Rutland 2016-01-25 @426 pud_clear_fixmap();
ee017ee353506f Jianyong Wu 2022-02-01 427 if (system_state != SYSTEM_BOOTING)
ee017ee353506f Jianyong Wu 2022-02-01 428 mutex_unlock(&fixmap_lock);
c1cc1552616d0f Catalin Marinas 2012-03-05 429 }
c1cc1552616d0f Catalin Marinas 2012-03-05 430
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