| Message ID | 20210809093750.131091-2-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: support page mapping percpu first chunk allocator | expand |
On Mon, Aug 09, 2021 at 05:37:48PM +0800, Kefeng Wang wrote: > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index d5cd52805149..1e8fe08725b8 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2238,11 +2238,17 @@ void __init vm_area_add_early(struct vm_struct *vm) > */ > void __init vm_area_register_early(struct vm_struct *vm, size_t align) > { > - static size_t vm_init_off __initdata; > - unsigned long addr; > - > - addr = ALIGN(VMALLOC_START + vm_init_off, align); > - vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; > + struct vm_struct *head = vmlist, *curr, *next; > + unsigned long addr = ALIGN(VMALLOC_START, align); > + > + while (head != NULL) { Nitpick: I'd use the same pattern as in vm_area_add_early(), i.e. a 'for' loop. You might as well insert it directly than calling the add function and going through the loop again. Not a strong preference either way. > + next = head->next; > + curr = head; > + head = next; > + addr = ALIGN((unsigned long)curr->addr + curr->size, align); > + if (next && (unsigned long)next->addr - addr > vm->size) Is greater or equal sufficient? > + break; > + } > > vm->addr = (void *)addr; Another nitpick: it's very unlikely on a 64-bit architecture but not impossible on 32-bit to hit VMALLOC_END here. Maybe some BUG_ON.
On 2021/8/26 1:59, Catalin Marinas wrote: > On Mon, Aug 09, 2021 at 05:37:48PM +0800, Kefeng Wang wrote: >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> index d5cd52805149..1e8fe08725b8 100644 >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -2238,11 +2238,17 @@ void __init vm_area_add_early(struct vm_struct *vm) >> */ >> void __init vm_area_register_early(struct vm_struct *vm, size_t align) >> { >> - static size_t vm_init_off __initdata; >> - unsigned long addr; >> - >> - addr = ALIGN(VMALLOC_START + vm_init_off, align); >> - vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; >> + struct vm_struct *head = vmlist, *curr, *next; >> + unsigned long addr = ALIGN(VMALLOC_START, align); >> + >> + while (head != NULL) { > Nitpick: I'd use the same pattern as in vm_area_add_early(), i.e. a > 'for' loop. You might as well insert it directly than calling the add > function and going through the loop again. Not a strong preference > either way. > >> + next = head->next; >> + curr = head; >> + head = next; >> + addr = ALIGN((unsigned long)curr->addr + curr->size, align); >> + if (next && (unsigned long)next->addr - addr > vm->size) > Is greater or equal sufficient? > >> + break; >> + } >> >> vm->addr = (void *)addr; > Another nitpick: it's very unlikely on a 64-bit architecture but not > impossible on 32-bit to hit VMALLOC_END here. Maybe some BUG_ON. Hi Catalin, thank for your review, I will update in the next version, Could you take a look the following change, is it OK? void __init vm_area_register_early(struct vm_struct *vm, size_t align) { struct vm_struct *next, *cur, **p; unsigned long addr = ALIGN(VMALLOC_START, align); BUG_ON(vmap_initialized); for (p = &vmlist; (cur = *p) != NULL, next = cur->next; p = &next) { addr = ALIGN((unsigned long)cur->addr + cur->size, align); if (next && (unsigned long)next->addr - addr >= vm->size) { p = &next; break; } } BUG_ON(addr > VMALLOC_END - vm->size); vm->addr = (void *)addr; vm->next = *p; *p = vm; } >
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d5cd52805149..1e8fe08725b8 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2238,11 +2238,17 @@ void __init vm_area_add_early(struct vm_struct *vm) */ void __init vm_area_register_early(struct vm_struct *vm, size_t align) { - static size_t vm_init_off __initdata; - unsigned long addr; - - addr = ALIGN(VMALLOC_START + vm_init_off, align); - vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; + struct vm_struct *head = vmlist, *curr, *next; + unsigned long addr = ALIGN(VMALLOC_START, align); + + while (head != NULL) { + next = head->next; + curr = head; + head = next; + addr = ALIGN((unsigned long)curr->addr + curr->size, align); + if (next && (unsigned long)next->addr - addr > vm->size) + break; + } vm->addr = (void *)addr;
There are some fixed locations in the vmalloc area be reserved in ARM(see iotable_init()) and ARM64(see map_kernel()), but for pcpu_page_first_chunk(), it calls vm_area_register_early() and choose VMALLOC_START as the start address of vmap area which could be conflicted with above address, then could trigger a BUG_ON in vm_area_add_early(). Let's choose the end of existing address range in vmlist as the start address instead of VMALLOC_START to avoid the BUG_ON. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- mm/vmalloc.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)