Date: Mon, 10 Apr 2017 13:15:57 -0700 From: Mark Millard <markmi@dsl-only.net> To: Konstantin Belousov <kostikbel@gmail.com> Cc: andrew@freebsd.org, freebsd-hackers@freebsd.org, freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: The arm64 fork-then-swap-out-then-swap-in failures: a program source for exploring them Message-ID: <876EA1E4-E5A9-411C-AFFD-989713037C19@dsl-only.net> In-Reply-To: <585B43F7-D4C8-431A-BFFE-68B48C3214AE@dsl-only.net> References: <4DEA2D76-9F27-426D-A8D2-F07B16575FB9@dsl-only.net> <163B37B0-55D6-498E-8F52-9A95C036CDFA@dsl-only.net> <08E7A5B0-8707-4479-9D7A-272C427FF643@dsl-only.net> <20170409122715.GF1788@kib.kiev.ua> <9D152170-5F19-47A2-A06A-66F83CA88A09@dsl-only.net> <9DCAF95B-39A5-4346-88FC-6AFDEE8CF9BB@dsl-only.net> <8FFE95AA-DB40-4D1E-A103-4BA9FCC6EDEE@dsl-only.net> <89D6D677-3BE2-45E2-A902-CC6A0305F3F9@dsl-only.net> <585B43F7-D4C8-431A-BFFE-68B48C3214AE@dsl-only.net>
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On 2017-Apr-10, at 2:51 AM, Mark Millard <markmi at dsl-only.net> wrote:
> On 2017-Apr-9, at 5:10 PM, Mark Millard <markmi at dsl-only.net> wrote:
>
>> On 2017-Apr-9, at 10:24 AM, Mark Millard <markmi at dsl-only.net> wrote:
>>
>>> On 2017-Apr-9, at 5:27 AM, Konstantin Belousov <kostikbel@gmail.com> wrote:
>>
>>>
>>>> Hmm, could you try the following patch, I did not even compiled it.
>>>
>>> I'll try it later today.
>>>
>>>> diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
>>>> index 3d5756ba891..55aa402eb1c 100644
>>>> --- a/sys/arm64/arm64/pmap.c
>>>> +++ b/sys/arm64/arm64/pmap.c
>>>> @@ -2481,6 +2481,11 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
>>>> sva += L3_SIZE) {
>>>> l3 = pmap_load(l3p);
>>>> if (pmap_l3_valid(l3)) {
>>>> + if ((l3 & ATTR_SW_MANAGED) &&
>>>> + pmap_page_dirty(l3)) {
>>>> + vm_page_dirty(PHYS_TO_VM_PAGE(l3 &
>>>> + ~ATTR_MASK));
>>>> + }
>>>> pmap_set(l3p, ATTR_AP(ATTR_AP_RO));
>>>> PTE_SYNC(l3p);
>>>> /* XXX: Use pmap_invalidate_range */
>>
>>
>> Preliminary testing indicates that this fixes the
>> some-pages-become-zero problem for fork-then-swapout/in.
>>
>> Thanks!
>>
>> I'll see if a buildworld can go through without being stopped
>> by the type of issue. But that will take a while. (It is how
>> I originally ran into the problem(s) that others had been
>> reporting on the lists.)
>
> buildworld buildkernel completed non-stop for the first time
> on a BPI-M3 board.
I had been thinking of the BPI-M3 for other reasons
and typed that instead of the correct: Pine64+ 2GB.
(True elsewhere as well.) I do really mean arm64
here, not armv7.
> Looks good for a check-in to svn to me (head and stable/11).
>
> This combined with 2017-Feb-15's -r313772's fix to the fork
> trampline code's updating of sp_el0 makes arm64 far more stable
> for my purposes.
>
> -r313772 was never MFC'd to stable/11. In my view it should be.
===
Mark Millard
markmi at dsl-only.net
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