Hello sorry for build warning. I've changed %d to %ld reported by kbuild. Let me attach full patch again below. -------------------------------------------------- Even on 64 bit kernel, the mmap failure can happen for a 32 bit task. Virtual memory space shortage of a task on mmap is reported to userspace as -ENOMEM. It can be confused as physical memory shortage of overall system. The vm_unmapped_area can be called to by some drivers or other kernel core system like filesystem. It can be hard to know which code layer returns the -ENOMEM. Print error log of vm_unmapped_area with rate limited. Without rate limited, soft lockup ocurrs on infinite mmap sytem call. i.e.) <3>[ 576.024088] [6: mmap_infinite:14251] mmap: vm_unmapped_area err:-12 total_vm:0xfee08 flags:0x1 len:0xa00000 low:0x8000 high:0xf3f63000 Fixed type mismatching on previous patch which is reported by kbuild. Reported-by: kbuild test robot <lkp@xxxxxxxxx> Signed-off-by: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx> --- include/linux/mm.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 52269e56c514..ecf9e1fcde79 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2379,10 +2379,19 @@ extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info); static inline unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info) { + unsigned long addr; + if (info->flags & VM_UNMAPPED_AREA_TOPDOWN) - return unmapped_area_topdown(info); + addr = unmapped_area_topdown(info); else - return unmapped_area(info); + addr = unmapped_area(info); + + if (IS_ERR_VALUE(addr) && printk_ratelimit()) { + pr_err("%s err:%ld total_vm:0x%lx flags:0x%lx len:0x%lx low:0x%lx high:0x%lx\n", + __func__, addr, current->mm->total_vm, info->flags, + info->length, info->low_limit, info->high_limit); + } + return addr; } On 2020년 03월 04일 12:02, Jaewon Kim wrote: > Even on 64 bit kernel, the mmap failure can happen for a 32 bit task. > Virtual memory space shortage of a task on mmap is reported to userspace > as -ENOMEM. It can be confused as physical memory shortage of overall > system. > > The vm_unmapped_area can be called to by some drivers or other kernel > core system like filesystem. It can be hard to know which code layer > returns the -ENOMEM. > > Print error log of vm_unmapped_area with rate limited. Without rate > limited, soft lockup ocurrs on infinite mmap sytem call. > > i.e.) > <3>[ 576.024088] [6: mmap_infinite:14251] mmap: vm_unmapped_area err:-12 total_vm:0xfee08 flags:0x1 len:0xa00000 low:0x8000 high:0xf3f63000 > > Signed-off-by: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx> > --- > include/linux/mm.h | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 52269e56c514..ee822d65ebb7 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2379,10 +2379,19 @@ extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info); > static inline unsigned long > vm_unmapped_area(struct vm_unmapped_area_info *info) > { > + unsigned long addr; > + > if (info->flags & VM_UNMAPPED_AREA_TOPDOWN) > - return unmapped_area_topdown(info); > + addr = unmapped_area_topdown(info); > else > - return unmapped_area(info); > + addr = unmapped_area(info); > + > + if (IS_ERR_VALUE(addr) && printk_ratelimit()) { > + pr_err("%s err:%d total_vm:0x%lx flags:0x%lx len:0x%lx low:0x%lx high:0x%lx\n", > + __func__, addr, current->mm->total_vm, info->flags, > + info->length, info->low_limit, info->high_limit); > + } > + return addr; > } > > /* truncate.c */