From: Yisheng Xie <xieyisheng1@xxxxxxxxxx> Subject: vmalloc: show lazy-purged vma info in vmallocinfo When ioremap a 67112960 bytes vm_area with the vmallocinfo: [..] 0xec79b000-0xec7fa000 389120 ftl_add_mtd+0x4d0/0x754 pages=94 vmalloc 0xec800000-0xecbe1000 4067328 kbox_proc_mem_write+0x104/0x1c4 phys=8b520000 ioremap we get the result: 0xf1000000-0xf5001000 67112960 devm_ioremap+0x38/0x7c phys=40000000 ioremap For the align for ioremap must be less than '1 << IOREMAP_MAX_ORDER': if (flags & VM_IOREMAP) align = 1ul << clamp_t(int, get_count_order_long(size), PAGE_SHIFT, IOREMAP_MAX_ORDER); So it makes idiot like me a litte puzzled why this was a jump the vm_area from 0xec800000-0xecbe1000 to 0xf1000000-0xf5001000, and leaving 0xed000000-0xf1000000 as a big hole. This patch is to show all of vm_area, including vmas which are freeing but still in the vmap_area_list, to make it more clear about why we will get 0xf1000000-0xf5001000 in the above case. And we will get a vmallocinfo like: [..] 0xec79b000-0xec7fa000 389120 ftl_add_mtd+0x4d0/0x754 pages=94 vmalloc 0xec800000-0xecbe1000 4067328 kbox_proc_mem_write+0x104/0x1c4 phys=8b520000 ioremap [..] 0xece7c000-0xece7e000 8192 unpurged vm_area 0xece7e000-0xece83000 20480 vm_map_ram 0xf0099000-0xf00aa000 69632 vm_map_ram after apply this patch. Link: http://lkml.kernel.org/r/1496649682-20710-1-git-send-email-xieyisheng1@xxxxxxxxxx Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: zijun_hu <zijun_hu@xxxxxxx> Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> Cc: Hanjun Guo <guohanjun@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmalloc.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff -puN mm/vmalloc.c~vmalloc-show-more-detail-info-in-vmallocinfo-for-clarify mm/vmalloc.c --- a/mm/vmalloc.c~vmalloc-show-more-detail-info-in-vmallocinfo-for-clarify +++ a/mm/vmalloc.c @@ -325,6 +325,7 @@ EXPORT_SYMBOL(vmalloc_to_pfn); /*** Global kva allocator ***/ +#define VM_LAZY_FREE 0x02 #define VM_VM_AREA 0x04 static DEFINE_SPINLOCK(vmap_area_lock); @@ -1497,6 +1498,7 @@ struct vm_struct *remove_vm_area(const v spin_lock(&vmap_area_lock); va->vm = NULL; va->flags &= ~VM_VM_AREA; + va->flags |= VM_LAZY_FREE; spin_unlock(&vmap_area_lock); vmap_debug_free_range(va->va_start, va->va_end); @@ -2704,8 +2706,14 @@ static int s_show(struct seq_file *m, vo * s_show can encounter race with remove_vm_area, !VM_VM_AREA on * behalf of vmap area is being tear down or vm_map_ram allocation. */ - if (!(va->flags & VM_VM_AREA)) + if (!(va->flags & VM_VM_AREA)) { + seq_printf(m, "0x%pK-0x%pK %7ld %s\n", + (void *)va->va_start, (void *)va->va_end, + va->va_end - va->va_start, + va->flags & VM_LAZY_FREE ? "unpurged vm_area" : "vm_map_ram"); + return 0; + } v = va->vm; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
