On 10/11/23 15:47, Sergey Senozhatsky wrote: > On (23/10/05 20:20), Mike Kravetz wrote: > > Allocation of a hugetlb page for the hugetlb pool is done by the routine > > alloc_pool_huge_page. This routine will allocate contiguous pages from > > a low level allocator, prep the pages for usage as a hugetlb page and > > then add the resulting hugetlb page to the pool. > > > > In the 'prep' stage, optional vmemmap optimization is done. For > > performance reasons we want to perform vmemmap optimization on multiple > > hugetlb pages at once. To do this, restructure the hugetlb pool > > allocation code such that vmemmap optimization can be isolated and later > > batched. > > > > The code to allocate hugetlb pages from bootmem was also modified to > > allow batching. > > > > No functional changes, only code restructure. > > I'm afraid there are some functional changes. > Hi Sergey, Sorry for the delay. Not ignoring your report but chasing this in another thread. https://lore.kernel.org/linux-mm/20231018222003.GA21776@monkey/ Quick question. Are you using LLVM/clang in your builds? My guess is that you are hitting the same issue. That BUG at mm/hugetlb.c:3180 should not be checked/executed unless you allocate gigantic hugetlb pages on the kernel command line. Suspect you are not doing this, and loop code is being run when it should not. -- Mike Kravetz > [...] > # good: [9e6c86c616f7d4b166c12f1ea9b69831f85c4a86] hugetlb: optimize update_and_free_pages_bulk to avoid lock cycles > git bisect good 9e6c86c616f7d4b166c12f1ea9b69831f85c4a86 > # bad: [1d50db09471e2a67272cee6e004ffed380ac571b] Merge branch 'master' of git://linuxtv.org/mchehab/media-next.git > git bisect bad 1d50db09471e2a67272cee6e004ffed380ac571b > # good: [80b14e865ea20ddc20aae61e2c106ebb03257cd3] bcachefs: Lower BCH_NAME_MAX to 512 > git bisect good 80b14e865ea20ddc20aae61e2c106ebb03257cd3 > # bad: [31d068de8a0de2c44168bbd8a62da21a7bc76051] Merge branch 'for-linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git > git bisect bad 31d068de8a0de2c44168bbd8a62da21a7bc76051 > # bad: [0bb194b29fa6296a74b989e0f7f2db4fc11d8012] Merge branch 'perf-tools-next' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git > git bisect bad 0bb194b29fa6296a74b989e0f7f2db4fc11d8012 > # good: [62001c9bf6aad59dc800c16613e5440b9226c252] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/wpan/wpan.git > git bisect good 62001c9bf6aad59dc800c16613e5440b9226c252 > # good: [21d856352ab78daffb9d05296b87b570f3afac33] Merge branch 'mm-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > git bisect good 21d856352ab78daffb9d05296b87b570f3afac33 > # good: [7fded33c6971b6c8e87cbbf48e74536aacca2991] perf test: Add pmu-event test for "Compat" and new event_field. > git bisect good 7fded33c6971b6c8e87cbbf48e74536aacca2991 > # good: [4c37b665186a5e2907bf0308474ac3f15eb847da] compiler.h: move __is_constexpr() to compiler.h > git bisect good 4c37b665186a5e2907bf0308474ac3f15eb847da > # bad: [3424f8f382bd4d30e01eaf316823321ef7bd1560] mm: delete checks for xor_unlock_is_negative_byte() > git bisect bad 3424f8f382bd4d30e01eaf316823321ef7bd1560 > # bad: [b5c6a60fe5b0339ba9c54f9f871db5c4a0e47906] iomap: protect read_bytes_pending with the state_lock > git bisect bad b5c6a60fe5b0339ba9c54f9f871db5c4a0e47906 > # bad: [bfae92330ddc44968c628c0085082d25061495a4] hugetlb: batch PMD split for bulk vmemmap dedup > git bisect bad bfae92330ddc44968c628c0085082d25061495a4 > # bad: [fb59f2cb8956f3888d2e0b438cc503565aa3c405] hugetlb: perform vmemmap optimization on a list of pages > git bisect bad fb59f2cb8956f3888d2e0b438cc503565aa3c405 > # bad: [bfb41d6b2fe148c939366957ea9cb9aa72d59c4c] hugetlb: restructure pool allocations > git bisect bad bfb41d6b2fe148c939366957ea9cb9aa72d59c4c > # first bad commit: [bfb41d6b2fe148c939366957ea9cb9aa72d59c4c] hugetlb: restructure pool allocations > > bfb41d6b2fe148c939366957ea9cb9aa72d59c4c is the first bad commit > > commit bfb41d6b2fe148c939366957ea9cb9aa72d59c4c > Author: Mike Kravetz > Date: Thu Oct 5 20:20:04 2023 -0700 > > hugetlb: restructure pool allocations > > > Bugs-on linux-next: > > [ 0.827640] ------------[ cut here ]------------ > [ 0.828608] kernel BUG at mm/hugetlb.c:3180!
