From: Liam Howlett <liam.howlett@oracle.com>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Song Liu <songliubraving@fb.com>,
Davidlohr Bueso <dave@stgolabs.net>,
"Paul E . McKenney" <paulmck@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Laurent Dufour <ldufour@linux.ibm.com>,
David Rientjes <rientjes@google.com>,
Axel Rasmussen <axelrasmussen@google.com>,
Suren Baghdasaryan <surenb@google.com>,
Rik van Riel <riel@surriel.com>,
Peter Zijlstra <peterz@infradead.org>,
Michel Lespinasse <walken.cr@gmail.com>,
Jerome Glisse <jglisse@redhat.com>,
Minchan Kim <minchan@google.com>,
Joel Fernandes <joelaf@google.com>,
Rom Lemarchand <romlem@google.com>
Subject: Re: [PATCH v4 49/66] bpf: Remove VMA linked list
Date: Tue, 25 Jan 2022 21:37:06 +0000 [thread overview]
Message-ID: <20220125213649.dlmtd6mj6malcbo6@revolver> (raw)
In-Reply-To: <57e33b08-f578-b84d-664b-939d9100d54d@suse.cz>
* Vlastimil Babka <vbabka@suse.cz> [220119 12:05]:
> On 12/1/21 15:30, Liam Howlett wrote:
> > From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
> >
> > Use vma_next() and remove reference to the start of the linked list
> >
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
> > ---
> > kernel/bpf/task_iter.c | 21 ++++-----------------
> > 1 file changed, 4 insertions(+), 17 deletions(-)
> >
> > diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
> > index b48750bfba5a..2d964743f1e6 100644
> > --- a/kernel/bpf/task_iter.c
> > +++ b/kernel/bpf/task_iter.c
> > @@ -299,8 +299,8 @@ struct bpf_iter_seq_task_vma_info {
> > };
> >
> > enum bpf_task_vma_iter_find_op {
> > - task_vma_iter_first_vma, /* use mm->mmap */
> > - task_vma_iter_next_vma, /* use curr_vma->vm_next */
> > + task_vma_iter_first_vma, /* use find_vma() with addr 0 */
> > + task_vma_iter_next_vma, /* use vma_next() with curr_vma */
> > task_vma_iter_find_vma, /* use find_vma() to find next vma */
> > };
> >
> > @@ -400,24 +400,11 @@ task_vma_seq_get_next(struct bpf_iter_seq_task_vma_info *info)
> >
> > switch (op) {
> > case task_vma_iter_first_vma:
> > - curr_vma = curr_task->mm->mmap;
> > + curr_vma = find_vma(curr_task->mm, 0);
> > break;
> > case task_vma_iter_next_vma:
> > - curr_vma = curr_vma->vm_next;
> > - break;
> > case task_vma_iter_find_vma:
> > - /* We dropped mmap_lock so it is necessary to use find_vma
> > - * to find the next vma. This is similar to the mechanism
> > - * in show_smaps_rollup().
> > - */
> > - curr_vma = find_vma(curr_task->mm, info->prev_vm_end - 1);
> > - /* case 1) and 4.2) above just use curr_vma */
> > -
> > - /* check for case 2) or case 4.1) above */
> > - if (curr_vma &&
> > - curr_vma->vm_start == info->prev_vm_start &&
> > - curr_vma->vm_end == info->prev_vm_end)
> > - curr_vma = curr_vma->vm_next;
> > + curr_vma = find_vma(curr_task->mm, curr_vma->vm_end);
>
> Are you sure curr_vma is valid here and we can read its vm_end? Because I
> have no idea, but lots of doubts.
I am not sure. I'm going to drop this patch and take the more
conservative but safer v3 version.
>
> > break;
> > }
> > if (!curr_vma) {
>
>
next prev parent reply other threads:[~2022-01-25 21:37 UTC|newest]
Thread overview: 181+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-01 14:29 [PATCH v4 00/66] Introducing the Maple Tree Liam Howlett
2021-12-01 14:29 ` [PATCH v4 01/66] radix tree test suite: Add pr_err define Liam Howlett
2021-12-01 14:29 ` [PATCH v4 02/66] radix tree test suite: Add kmem_cache_set_non_kernel() Liam Howlett
2021-12-01 14:29 ` [PATCH v4 04/66] radix tree test suite: Add support for slab bulk APIs Liam Howlett
2021-12-01 14:29 ` [PATCH v4 03/66] radix tree test suite: Add allocation counts and size to kmem_cache Liam Howlett
2021-12-01 14:29 ` [PATCH v4 06/66] mm: Start tracking VMAs with maple tree Liam Howlett
2021-12-07 18:01 ` Vlastimil Babka
2021-12-08 18:11 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 05/66] Maple Tree: Add new data structure Liam Howlett
2021-12-07 15:34 ` Vlastimil Babka
2021-12-08 15:47 ` Matthew Wilcox
2021-12-08 17:20 ` Liam Howlett
2021-12-15 12:54 ` Vlastimil Babka
2021-12-15 17:52 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 07/66] mm: Add VMA iterator Liam Howlett
2021-12-09 15:26 ` Vlastimil Babka
2021-12-10 2:02 ` Liam Howlett
2021-12-10 15:08 ` Vlastimil Babka
2021-12-10 18:24 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 09/66] mm/mmap: Use the maple tree in find_vma() instead of the rbtree Liam Howlett
2021-12-15 13:05 ` Vlastimil Babka
2021-12-15 18:09 ` Liam Howlett
2022-01-13 15:46 ` Vlastimil Babka
2021-12-01 14:29 ` [PATCH v4 08/66] mmap: Use the VMA iterator in count_vma_pages_range() Liam Howlett
2021-12-09 15:54 ` Vlastimil Babka
2021-12-10 1:35 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 11/66] mm/mmap: Use maple tree for unmapped_area{_topdown} Liam Howlett
2021-12-15 16:43 ` Vlastimil Babka
2021-12-15 18:28 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 10/66] mm/mmap: Use the maple tree for find_vma_prev() instead of the rbtree Liam Howlett
2021-12-15 14:33 ` Vlastimil Babka
2021-12-15 16:40 ` Vlastimil Babka
2021-12-15 18:19 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 12/66] kernel/fork: Use maple tree for dup_mmap() during forking Liam Howlett
2021-12-16 11:09 ` Vlastimil Babka
2022-01-03 16:45 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 14/66] proc: Remove VMA rbtree use from nommu Liam Howlett
2021-12-16 11:25 ` Vlastimil Babka
2021-12-01 14:29 ` [PATCH v4 13/66] damon: Convert __damon_va_three_regions to use the VMA iterator Liam Howlett
2021-12-01 14:29 ` [PATCH v4 15/66] mm: Convert vma_lookup() to use the Maple Tree Liam Howlett
2021-12-17 11:59 ` Vlastimil Babka
2022-01-03 17:07 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 16/66] mm: Remove rb tree Liam Howlett
2022-01-12 12:02 ` Vlastimil Babka
2022-01-17 1:12 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 19/66] mm: Optimize find_exact_vma() to use vma_lookup() Liam Howlett
2022-01-12 16:31 ` Vlastimil Babka
2021-12-01 14:29 ` [PATCH v4 17/66] mmap: Change zeroing of maple tree in __vma_adjust Liam Howlett
2022-01-12 14:55 ` Vlastimil Babka
2022-01-17 20:02 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 18/66] xen: Use vma_lookup() in privcmd_ioctl_mmap() Liam Howlett
2022-01-12 16:01 ` Vlastimil Babka
2022-01-18 0:01 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 20/66] mm/khugepaged: Optimize collapse_pte_mapped_thp() by using vma_lookup() Liam Howlett
2022-01-12 16:42 ` Vlastimil Babka
2021-12-01 14:29 ` [PATCH v4 21/66] mm/mmap: Change do_brk_flags() to expand existing VMA and add do_brk_munmap() Liam Howlett
2022-01-13 12:59 ` Vlastimil Babka
2022-01-19 3:03 ` Liam Howlett
2022-01-21 12:41 ` Vlastimil Babka
2022-01-13 15:28 ` Vlastimil Babka
2022-01-19 15:51 ` Liam Howlett
2021-12-01 14:29 ` [PATCH v4 22/66] mm: Use maple tree operations for find_vma_intersection() and find_vma() Liam Howlett
2022-01-13 15:53 ` Vlastimil Babka
2022-01-19 16:56 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 23/66] mm/mmap: Use advanced maple tree API for mmap_region() Liam Howlett
2022-01-17 16:38 ` Vlastimil Babka
2022-01-21 18:11 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 24/66] mm: Remove vmacache Liam Howlett
2022-01-17 17:01 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 25/66] mm/mmap: Move mmap_region() below do_munmap() Liam Howlett
2021-12-01 14:30 ` [PATCH v4 27/66] mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap() Liam Howlett
2022-01-18 11:57 ` Vlastimil Babka
2022-01-22 1:53 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 26/66] mm/mmap: Reorganize munmap to use maple states Liam Howlett
2022-01-18 10:39 ` Vlastimil Babka
2022-01-21 19:31 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 29/66] parisc: Remove mmap linked list from cache handling Liam Howlett
2022-01-18 12:06 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 28/66] arm64: Remove mmap linked list from vdso Liam Howlett
2022-01-18 12:03 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 31/66] s390: Remove vma linked list walks Liam Howlett
2022-01-18 12:12 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 30/66] powerpc: Remove mmap " Liam Howlett
2022-01-18 12:10 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 32/66] x86: Remove vma " Liam Howlett
2022-01-18 12:12 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 33/66] xtensa: " Liam Howlett
2022-01-18 12:23 ` Vlastimil Babka
2022-01-25 16:17 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 34/66] cxl: Remove vma linked list walk Liam Howlett
2022-01-18 12:37 ` Vlastimil Babka
2022-01-25 16:32 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 36/66] um: " Liam Howlett
2022-01-18 18:41 ` Vlastimil Babka
2022-01-25 16:38 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 37/66] binfmt_elf: " Liam Howlett
2022-01-19 9:57 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 35/66] optee: " Liam Howlett
2022-01-18 18:15 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 38/66] coredump: " Liam Howlett
2022-01-19 10:31 ` Vlastimil Babka
2022-01-25 17:00 ` Matthew Wilcox
2021-12-01 14:30 ` [PATCH v4 39/66] binfmt_elf: Take the mmap lock when walking the VMA list Liam Howlett
2022-01-19 10:53 ` Vlastimil Babka
2022-01-31 17:41 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 42/66] fs/proc/task_mmu: Stop using linked list and highest_vm_end Liam Howlett
2022-01-21 11:52 ` Vlastimil Babka
2022-01-27 20:14 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 41/66] fs/proc/base: Use maple tree iterators in place of linked list Liam Howlett
2022-01-19 11:10 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 40/66] exec: Use VMA iterator instead " Liam Howlett
2022-01-19 11:06 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 43/66] userfaultfd: Use maple tree iterator to iterate VMAs Liam Howlett
2022-01-19 16:26 ` Vlastimil Babka
2022-01-25 20:47 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 44/66] ipc/shm: Use VMA iterator instead of linked list Liam Howlett
2022-01-21 12:25 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 46/66] perf: Use VMA iterator Liam Howlett
2022-01-19 16:47 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 45/66] acct: Use VMA iterator instead of linked list Liam Howlett
2022-01-19 16:44 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 47/66] sched: Use maple tree iterator to walk VMAs Liam Howlett
2022-01-19 16:49 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 48/66] fork: Use VMA iterator Liam Howlett
2022-01-19 16:51 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 49/66] bpf: Remove VMA linked list Liam Howlett
2022-01-19 17:04 ` Vlastimil Babka
2022-01-25 21:37 ` Liam Howlett [this message]
2021-12-01 14:30 ` [PATCH v4 50/66] mm/gup: Use maple tree navigation instead of " Liam Howlett
2022-01-19 17:39 ` Vlastimil Babka
2022-01-25 21:54 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 52/66] mm/ksm: Use maple tree iterators instead of vma " Liam Howlett
2022-01-19 17:58 ` Vlastimil Babka
2022-01-26 2:29 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 51/66] mm/khugepaged: " Liam Howlett
2022-01-19 17:48 ` Vlastimil Babka
2022-01-25 22:03 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 55/66] mm/mempolicy: " Liam Howlett
2022-01-20 11:58 ` Vlastimil Babka
2022-01-26 2:48 ` Liam Howlett
2022-01-26 9:22 ` Vlastimil Babka
2022-01-27 17:25 ` Liam Howlett
2022-01-27 17:33 ` Vlastimil Babka
2022-01-27 23:03 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 54/66] mm/memcontrol: Stop using mm->highest_vm_end Liam Howlett
2022-01-20 11:21 ` Vlastimil Babka
2022-01-26 2:34 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 53/66] mm/madvise: Use vma_find() instead of vma linked list Liam Howlett
2022-01-19 18:00 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 56/66] mm/mlock: Use maple tree iterators " Liam Howlett
2022-01-20 12:16 ` Vlastimil Babka
2022-01-26 16:41 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 57/66] mm/mprotect: Use maple tree navigation " Liam Howlett
2022-01-20 12:23 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 59/66] mm/msync: Use vma_find() " Liam Howlett
2022-01-20 12:42 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 58/66] mm/mremap: " Liam Howlett
2022-01-20 12:27 ` Vlastimil Babka
2022-01-26 16:59 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 60/66] mm/oom_kill: Use maple tree iterators " Liam Howlett
2022-01-20 12:43 ` Vlastimil Babka
2022-01-26 17:02 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 61/66] mm/pagewalk: Use vma_find() " Liam Howlett
2022-01-20 12:43 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 62/66] mm/swapfile: Use maple tree iterator " Liam Howlett
2022-01-20 12:46 ` Vlastimil Babka
2022-01-26 17:08 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 63/66] i915: Use the VMA iterator Liam Howlett
2022-01-20 14:59 ` Vlastimil Babka
2022-01-20 15:50 ` Matthew Wilcox
2022-01-20 17:39 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 64/66] nommu: Remove uses of VMA linked list Liam Howlett
2022-01-20 15:06 ` Vlastimil Babka
2022-01-20 15:54 ` Matthew Wilcox
2022-01-20 17:06 ` Vlastimil Babka
2022-01-27 16:36 ` Liam Howlett
2021-12-01 14:30 ` [PATCH v4 66/66] mm/mmap: Drop range_has_overlap() function Liam Howlett
2022-01-21 9:51 ` Vlastimil Babka
2021-12-01 14:30 ` [PATCH v4 65/66] mm: Remove the vma linked list Liam Howlett
2022-01-20 17:41 ` Vlastimil Babka
2022-01-26 20:29 ` Liam Howlett
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