On Fri, 2023-06-09 at 12:20 +0100, Russell King (Oracle) wrote: > > External email : Please do not click links or open attachments until > you have verified the sender or the content. > On Fri, Jun 09, 2023 at 07:09:00PM +0800, jim.tsai wrote: > > Export symbols for arch_vma_name and smap_gather_stats > > functions so that we can detect the memory leak issues. > > Besides, we can know which memory type is leaked, too. > > This commit description doesn't give enough information. How does > exporting arch_vma_name() help with detecting memory leak issues? > > You haven't included any users of these new exports, so the initial > reaction is going to be negative - please include the users of these > new symbols in your patch set. > > Thanks. > > -- > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last! Hi Russell, arch_vma_name() is to get the heap infromation from a user process. We use these two export functions from our kernel module to get a specific user process's memory information and heap usage. Furthermore, we can use such information to detect the memory leak issues. The example code is as follows: /*example code*/ void m_map_vma(struct vm_area_struct *vma, unsigned long cur_pss, unsigned long *native_heap, unsigned long *java_heap) { struct mm_struct *mm = vma->vm_mm; const char *name = NULL; ... name = arch_vma_name(vma); if (!name) { struct anon_vma_name *anon_name; ... anon_name = m_anon_vma_name(vma); if (anon_name) { if (strstr(anon_name->name, "scudo")) (*native_heap) += cur_pss; else if (strstr(anon_name->name, "libc_malloc")) (*native_heap) += cur_pss; else if (strstr(anon_name->name, "GWP-ASan")) (*native_heap) += cur_pss; else if (strstr(anon_name->name, "dalvik-alloc space")) (*java_heap) += cur_pss; else if (strstr(anon_name->name, "dalvik-main space")) (*java_heap) += cur_pss; ... } } } void calculate_process_memory(struct task_struct *t) { struct mm_struct *mm = NULL; struct vm_area_struct *vma = NULL; struct mem_size_stats mss; unsigned long pss, uss, rss, swap, cur_pss; unsigned long java_heap = 0, native_heap = 0; struct vma_iterator vmi; get_task_struct(t); mm = t->mm; if (mm) { memset(&mss, 0, sizeof(mss)); mmgrab(mm); mmap_read_lock(mm); vma_iter_init(&vmi, mm, 0); for_each_vma(vmi, vma) { cur_pss = (unsigned long)(mss.pss >> PSS_SHIFT); smap_gather_stats(vma, &mss, 0); cur_pss = ((unsigned long)(mss.pss >> PSS_SHIFT)) - cur_pss; cur_pss = cur_pss / 1024; m_map_vma(vma, cur_pss, &native_heap, &java_heap); } mmap_read_unlock(mm); mmdrop(mm); } put_task_struct(t); ... } Thanks Jim
