| Message ID | 20210107092652.3438696-2-atish.patra@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Assorted fixes for RV32 | expand |
Hi Atish, On Thu, Jan 7, 2021 at 10:28 AM Atish Patra <atish.patra@wdc.com> wrote: > Currently, resource tree allocates memory blocks while iterating on the > list. It leads to following kernel warning because memblock allocation > also invokes memory block reservation API. > > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:795 > __insert_resource+0x8e/0xd0 > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted > 5.10.0-00022-ge20097fb37e2-dirty #549 > [ 0.000000] epc: c00125c2 ra : c001262c sp : c1c01f50 > [ 0.000000] gp : c1d456e0 tp : c1c0a980 t0 : ffffcf20 > [ 0.000000] t1 : 00000000 t2 : 00000000 s0 : c1c01f60 > [ 0.000000] s1 : ffffcf00 a0 : ffffff00 a1 : c1c0c0c4 > [ 0.000000] a2 : 80c12b15 a3 : 80402000 a4 : 80402000 > [ 0.000000] a5 : c1c0c0c4 a6 : 80c12b15 a7 : f5faf600 > [ 0.000000] s2 : c1c0c0c4 s3 : c1c0e000 s4 : c1009a80 > [ 0.000000] s5 : c1c0c000 s6 : c1d48000 s7 : c1613b4c > [ 0.000000] s8 : 00000fff s9 : 80000200 s10: c1613b40 > [ 0.000000] s11: 00000000 t3 : c1d4a000 t4 : ffffffff > > This is also unnecessary as we can pre-compute the total memblocks required > for each memory region and allocate it before the loop. It save precious > boot time not going through memblock allocation code every time. > > Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree") > > Signed-off-by: Atish Patra <atish.patra@wdc.com> Thanks for your patch! I never saw the warning (on linux-on-litex-vexriscv), but instead I got: Failed to add a Kernel code resource at 40001000 after Initmem setup. Adding some debug info to init_resources() showed that the memblock.reserved list kept on increasing, until memory corruption happened (pointers started to look like ASCII strings), the error message above is printed, and after which the boot continued. Changing L1_CACHE_SHIFT in arch/riscv/include/asm/cache.h to 5 fixed that. With this patch, the error message above is no longer printed, so Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Noted that the kernel still crashes later, with Unable to handle kernel paging request at virtual address 61636473 Again, 0x61636473 looks like ASCII, and your PATCH 3/4 for L1_CACHE_SHIFT fixes that, too. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Thu, Jan 7, 2021 at 2:57 PM Atish Patra <atish.patra@wdc.com> wrote: > > Currently, resource tree allocates memory blocks while iterating on the > list. It leads to following kernel warning because memblock allocation > also invokes memory block reservation API. > > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:795 > __insert_resource+0x8e/0xd0 > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted > 5.10.0-00022-ge20097fb37e2-dirty #549 > [ 0.000000] epc: c00125c2 ra : c001262c sp : c1c01f50 > [ 0.000000] gp : c1d456e0 tp : c1c0a980 t0 : ffffcf20 > [ 0.000000] t1 : 00000000 t2 : 00000000 s0 : c1c01f60 > [ 0.000000] s1 : ffffcf00 a0 : ffffff00 a1 : c1c0c0c4 > [ 0.000000] a2 : 80c12b15 a3 : 80402000 a4 : 80402000 > [ 0.000000] a5 : c1c0c0c4 a6 : 80c12b15 a7 : f5faf600 > [ 0.000000] s2 : c1c0c0c4 s3 : c1c0e000 s4 : c1009a80 > [ 0.000000] s5 : c1c0c000 s6 : c1d48000 s7 : c1613b4c > [ 0.000000] s8 : 00000fff s9 : 80000200 s10: c1613b40 > [ 0.000000] s11: 00000000 t3 : c1d4a000 t4 : ffffffff > > This is also unnecessary as we can pre-compute the total memblocks required > for each memory region and allocate it before the loop. It save precious > boot time not going through memblock allocation code every time. > > Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree") > > Signed-off-by: Atish Patra <atish.patra@wdc.com> Looks good to me. Reviewed-by: Anup Patel <anup@brainfault.org> > --- > arch/riscv/kernel/setup.c | 24 +++++++++++++----------- > 1 file changed, 13 insertions(+), 11 deletions(-) > > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index 1d85e9bf783c..3fa3f26dde85 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -127,7 +127,9 @@ static void __init init_resources(void) > { > struct memblock_region *region = NULL; > struct resource *res = NULL; > - int ret = 0; > + struct resource *mem_res = NULL; > + size_t mem_res_sz = 0; > + int ret = 0, i = 0; > > code_res.start = __pa_symbol(_text); > code_res.end = __pa_symbol(_etext) - 1; > @@ -145,16 +147,17 @@ static void __init init_resources(void) > bss_res.end = __pa_symbol(__bss_stop) - 1; > bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > > + mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * sizeof(*mem_res); > + mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES); > + if (!mem_res) > + panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz); > /* > * Start by adding the reserved regions, if they overlap > * with /memory regions, insert_resource later on will take > * care of it. > */ > for_each_reserved_mem_region(region) { > - res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); > - if (!res) > - panic("%s: Failed to allocate %zu bytes\n", __func__, > - sizeof(struct resource)); > + res = &mem_res[i++]; > > res->name = "Reserved"; > res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; > @@ -171,8 +174,10 @@ static void __init init_resources(void) > * Ignore any other reserved regions within > * system memory. > */ > - if (memblock_is_memory(res->start)) > + if (memblock_is_memory(res->start)) { > + memblock_free((phys_addr_t) res, sizeof(struct resource)); > continue; > + } > > ret = add_resource(&iomem_resource, res); > if (ret < 0) > @@ -181,10 +186,7 @@ static void __init init_resources(void) > > /* Add /memory regions to the resource tree */ > for_each_mem_region(region) { > - res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); > - if (!res) > - panic("%s: Failed to allocate %zu bytes\n", __func__, > - sizeof(struct resource)); > + res = &mem_res[i++]; > > if (unlikely(memblock_is_nomap(region))) { > res->name = "Reserved"; > @@ -205,9 +207,9 @@ static void __init init_resources(void) > return; > > error: > - memblock_free((phys_addr_t) res, sizeof(struct resource)); > /* Better an empty resource tree than an inconsistent one */ > release_child_resources(&iomem_resource); > + memblock_free((phys_addr_t) mem_res, mem_res_sz); > } > > > -- > 2.25.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv Regards, Anup
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 1d85e9bf783c..3fa3f26dde85 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -127,7 +127,9 @@ static void __init init_resources(void) { struct memblock_region *region = NULL; struct resource *res = NULL; - int ret = 0; + struct resource *mem_res = NULL; + size_t mem_res_sz = 0; + int ret = 0, i = 0; code_res.start = __pa_symbol(_text); code_res.end = __pa_symbol(_etext) - 1; @@ -145,16 +147,17 @@ static void __init init_resources(void) bss_res.end = __pa_symbol(__bss_stop) - 1; bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * sizeof(*mem_res); + mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES); + if (!mem_res) + panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz); /* * Start by adding the reserved regions, if they overlap * with /memory regions, insert_resource later on will take * care of it. */ for_each_reserved_mem_region(region) { - res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); - if (!res) - panic("%s: Failed to allocate %zu bytes\n", __func__, - sizeof(struct resource)); + res = &mem_res[i++]; res->name = "Reserved"; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; @@ -171,8 +174,10 @@ static void __init init_resources(void) * Ignore any other reserved regions within * system memory. */ - if (memblock_is_memory(res->start)) + if (memblock_is_memory(res->start)) { + memblock_free((phys_addr_t) res, sizeof(struct resource)); continue; + } ret = add_resource(&iomem_resource, res); if (ret < 0) @@ -181,10 +186,7 @@ static void __init init_resources(void) /* Add /memory regions to the resource tree */ for_each_mem_region(region) { - res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); - if (!res) - panic("%s: Failed to allocate %zu bytes\n", __func__, - sizeof(struct resource)); + res = &mem_res[i++]; if (unlikely(memblock_is_nomap(region))) { res->name = "Reserved"; @@ -205,9 +207,9 @@ static void __init init_resources(void) return; error: - memblock_free((phys_addr_t) res, sizeof(struct resource)); /* Better an empty resource tree than an inconsistent one */ release_child_resources(&iomem_resource); + memblock_free((phys_addr_t) mem_res, mem_res_sz); }
Currently, resource tree allocates memory blocks while iterating on the list. It leads to following kernel warning because memblock allocation also invokes memory block reservation API. [ 0.000000] ------------[ cut here ]------------ [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:795 __insert_resource+0x8e/0xd0 [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.10.0-00022-ge20097fb37e2-dirty #549 [ 0.000000] epc: c00125c2 ra : c001262c sp : c1c01f50 [ 0.000000] gp : c1d456e0 tp : c1c0a980 t0 : ffffcf20 [ 0.000000] t1 : 00000000 t2 : 00000000 s0 : c1c01f60 [ 0.000000] s1 : ffffcf00 a0 : ffffff00 a1 : c1c0c0c4 [ 0.000000] a2 : 80c12b15 a3 : 80402000 a4 : 80402000 [ 0.000000] a5 : c1c0c0c4 a6 : 80c12b15 a7 : f5faf600 [ 0.000000] s2 : c1c0c0c4 s3 : c1c0e000 s4 : c1009a80 [ 0.000000] s5 : c1c0c000 s6 : c1d48000 s7 : c1613b4c [ 0.000000] s8 : 00000fff s9 : 80000200 s10: c1613b40 [ 0.000000] s11: 00000000 t3 : c1d4a000 t4 : ffffffff This is also unnecessary as we can pre-compute the total memblocks required for each memory region and allocate it before the loop. It save precious boot time not going through memblock allocation code every time. Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree") Signed-off-by: Atish Patra <atish.patra@wdc.com> --- arch/riscv/kernel/setup.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)