| Message ID | 20241025192106.957236-1-jthoughton@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Fri, Oct 25, 2024, at 19:21, James Houghton wrote: > Hi Andrew, > > The following diff applied to the second patch[1] fixes this error. The > diff is functionally a no-op; the get_pmd_pfn() immediately following > the code here would return -1 in the !pmd_present() case. > > I can send a brand new patch if you'd prefer. > > [1]: > https://lore.kernel.org/linux-mm/20241019012940.3656292-3-jthoughton@google.com/ I ran into another problem with the build failure below, and found that your fixup address this as well. Arnd In file included from <command-line>: In function 'pmdp_test_and_clear_young', inlined from 'walk_pmd_range_locked.constprop.isra' at mm/vmscan.c:3504:8: include/linux/compiler_types.h:517:45: error: call to '__compiletime_assert_401' declared with attribute error: BUILD_BUG failed 517 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^ include/linux/compiler_types.h:498:25: note: in definition of macro '__compiletime_assert' 498 | prefix ## suffix(); \ | ^~~~~~ include/linux/compiler_types.h:517:9: note: in expansion of macro '_compiletime_assert' 517 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:59:21: note: in expansion of macro 'BUILD_BUG_ON_MSG' 59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") | ^~~~~~~~~~~~~~~~ include/linux/pgtable.h:383:9: note: in expansion of macro 'BUILD_BUG' 383 | BUILD_BUG(); | ^~~~~~~~~
diff is functionally a no-op; the get_pmd_pfn() immediately following the code here would return -1 in the !pmd_present() case. I can send a brand new patch if you'd prefer. [1]: https://lore.kernel.org/linux-mm/20241019012940.3656292-3-jthoughton@google.com/ diff --git a/mm/vmscan.c b/mm/vmscan.c index 29c098790b01..70604eef0dd3 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3486,7 +3486,10 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long addr, struct vm_area /* don't round down the first address */ addr = i ? (*first & PMD_MASK) + i * PMD_SIZE : *first; - if (pmd_present(pmd[i]) && !pmd_trans_huge(pmd[i])) { + if (!pmd_present(pmd[i])) + goto next; + + if (!pmd_trans_huge(pmd[i])) { if (!walk->force_scan && should_clear_pmd_young() && !mm_has_notifiers(args->mm)) pmdp_test_and_clear_young(vma, addr, pmd + i);