On 06/03/2019 14:05, Mike Rapoport wrote: > On Wed, Mar 06, 2019 at 10:14:47AM +0000, Guillaume Tucker wrote: >> On 01/03/2019 23:23, Dan Williams wrote: >>> On Fri, Mar 1, 2019 at 1:05 PM Guillaume Tucker >>> <guillaume.tucker@xxxxxxxxxxxxx> wrote: >>> >>> Is there an early-printk facility that can be turned on to see how far >>> we get in the boot? >> >> Yes, I've done that now by enabling CONFIG_DEBUG_AM33XXUART1 and >> earlyprintk in the command line. Here's the result, with the >> commit cherry picked on top of next-20190304: >> >> https://lava.collabora.co.uk/scheduler/job/1526326 >> >> [ 1.379522] ti-sysc 4804a000.target-module: sysc_flags 00000222 != 00000022 >> [ 1.396718] Unable to handle kernel paging request at virtual address 77bb4003 >> [ 1.404203] pgd = (ptrval) >> [ 1.406971] [77bb4003] *pgd=00000000 >> [ 1.410650] Internal error: Oops: 5 [#1] ARM >> [...] >> [ 1.672310] [<c07051a0>] (clk_hw_create_clk.part.21) from [<c06fea34>] (devm_clk_get+0x4c/0x80) >> [ 1.681232] [<c06fea34>] (devm_clk_get) from [<c064253c>] (sysc_probe+0x28c/0xde4) >> >> It's always failing at that point in the code. Also when >> enabling "debug" on the kernel command line, the issue goes >> away (exact same binaries etc..): >> >> https://lava.collabora.co.uk/scheduler/job/1526327 >> >> For the record, here's the branch I've been using: >> >> https://gitlab.collabora.com/gtucker/linux/tree/beaglebone-black-next-20190304-debug >> >> The board otherwise boots fine with next-20190304 (SMP=n), and >> also with the patch applied but the shuffle configs set to n. >> >>> Were there any boot *successes* on ARM with shuffling enabled? I.e. >>> clues about what's different about the specific memory setup for >>> beagle-bone-black. >> >> Looking at the KernelCI results from next-20190215, it looks like >> only the BeagleBone Black with SMP=n failed to boot: >> >> https://kernelci.org/boot/all/job/next/branch/master/kernel/next-20190215/ >> >> Of course that's not all the ARM boards that exist out there, but >> it's a fairly large coverage already. >> >> As the kernel panic always seems to originate in ti-sysc.c, >> there's a chance it's only visible on that platform... I'm doing >> a KernelCI run now with my test branch to double check that, >> it'll take a few hours so I'll send an update later if I get >> anything useful out of it. Here's the result, there were a couple of failures but some were due to infrastructure errors (nyan-big) and I'm not sure about what was the problem with the meson boards: https://staging.kernelci.org/boot/all/job/gtucker/branch/kernelci-local/kernel/next-20190304-1-g4f0b547b03da/ So there's no clear indicator that the shuffle config is causing any issue on any other platform than the BeagleBone Black. >> In the meantime, I'm happy to try out other things with more >> debug configs turned on or any potential fixes someone might >> have. > > ARM is the only arch that sets ARCH_HAS_HOLES_MEMORYMODEL to 'y'. Maybe the > failure has something to do with it... > > Guillaume, can you try this patch: Sure, it doesn't seem to be fixing the problem though: https://lava.collabora.co.uk/scheduler/job/1527471 I've added the patch to the same branch based on next-20190304. I guess this needs to be debugged a little further to see what the panic really is about. I'll see if I can spend a bit more time on it this week, unless there's any BeagleBone expert available to help or if someone has another fix to try out. Guillaume > diff --git a/mm/shuffle.c b/mm/shuffle.c > index 3ce1248..4a04aac 100644 > --- a/mm/shuffle.c > +++ b/mm/shuffle.c > @@ -58,7 +58,8 @@ module_param_call(shuffle, shuffle_store, shuffle_show, &shuffle_param, 0400); > * For two pages to be swapped in the shuffle, they must be free (on a > * 'free_area' lru), have the same order, and have the same migratetype. > */ > -static struct page * __meminit shuffle_valid_page(unsigned long pfn, int order) > +static struct page * __meminit shuffle_valid_page(unsigned long pfn, int order, > + struct zone *z) > { > struct page *page; > > @@ -80,6 +81,9 @@ static struct page * __meminit shuffle_valid_page(unsigned long pfn, int order) > if (!PageBuddy(page)) > return NULL; > > + if (!memmap_valid_within(pfn, page, z)) > + return NULL; > + > /* > * ...is the page on the same list as the page we will > * shuffle it with? > @@ -123,7 +127,7 @@ void __meminit __shuffle_zone(struct zone *z) > * page_j randomly selected in the span @zone_start_pfn to > * @spanned_pages. > */ > - page_i = shuffle_valid_page(i, order); > + page_i = shuffle_valid_page(i, order, z); > if (!page_i) > continue; > > @@ -137,7 +141,7 @@ void __meminit __shuffle_zone(struct zone *z) > j = z->zone_start_pfn + > ALIGN_DOWN(get_random_long() % z->spanned_pages, > order_pages); > - page_j = shuffle_valid_page(j, order); > + page_j = shuffle_valid_page(j, order, z); > if (page_j && page_j != page_i) > break; > } > >
