Messages in this thread Patch in this message | | | Date | Fri, 11 Sep 2015 06:20:27 +0800 | From | Chen Gang <> | Subject | Re: [PATCH] mm/mmap.c: Remove useless statement "vma = NULL" in find_vma() |
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On 9/11/15 02:19, Oleg Nesterov wrote: > On 09/10, Chen Gang wrote: >> - If "addr>= vm_start", we return this vma (else continue searching). > > This is optimization, we can stop the search because in this case > vma == tmp is obviously the 1st vma with "addr < vm_end". >
OK, thanks.
I guess if we have additional comments for "if (tmp->vm_start <= addr)", the code will be more readable for readers (especially for newbies).
@@ -2064,7 +2064,7 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) if (tmp->vm_end > addr) { vma = tmp; if (tmp->vm_start <= addr) - break; + break; /* It must be 1st "addr < vm_end" */ rb_node = rb_node->rb_left; } else rb_node = rb_node->rb_right;
> I simply can't understand your concerns. Perhaps you can make a > patch, then it will be more clear what me-or-you have missed. >
I guess, we need not (it is my missing). :-)
Thanks. -- Chen Gang (陈刚)
Open, share, and attitude like air, water, and life which God blessed
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