From: Peng Zhang <zhangpeng.00@bytedance.com>
To: rppt@kernel.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] memblock: Avoid useless checks in memblock_merge_regions().
Date: Sun, 29 Jan 2023 17:14:19 +0800 [thread overview]
Message-ID: <2ee31efb-a07f-6132-88fd-d69ad180cf33@bytedance.com> (raw)
In-Reply-To: <20230129090034.12310-3-zhangpeng.00@bytedance.com>
Hi, Mike
> @@ -581,7 +586,7 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
> bool insert = false;
> phys_addr_t obase = base;
> phys_addr_t end = base + memblock_cap_size(base, &size);
> - int idx, nr_new;
> + int idx, nr_new, start_rgn = -1, end_rgn;
> struct memblock_region *rgn;
>
> if (!size)
> @@ -635,10 +640,14 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
> #endif
> WARN_ON(flags != rgn->flags);
> nr_new++;
> - if (insert)
> + if (insert) {
> + if (start_rgn == -1)
We can't initialize start_rgn with 0 and use if(!start_rgn).
If start_rgn is equal to 0, it will be reassigned. It is possible that
we will eventually need start_rgn to be equal to 0, and it may be
reassigned to a larger value that does not meet expectations.
Thanks.
> + start_rgn = idx;
> + end_rgn = idx + 1;
> memblock_insert_region(type, idx++, base,
> rbase - base, nid,
> flags);
> + }
> }
> /* area below @rend is dealt with, forget about it */
> base = min(rend, end);
> @@ -647,9 +656,13 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
> /* insert the remaining portion */
> if (base < end) {
> nr_new++;
> - if (insert)
> + if (insert) {
> + if (start_rgn == -1)
> + start_rgn = idx;
> + end_rgn = idx + 1;
> memblock_insert_region(type, idx, base, end - base,
> nid, flags);
> + }
> }
>
> if (!nr_new)
> @@ -666,7 +679,7 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
> insert = true;
> goto repeat;
> } else {
> - memblock_merge_regions(type);
> + memblock_merge_regions(type, start_rgn, end_rgn);
> return 0;
> }
> }
> @@ -902,7 +915,7 @@ static int __init_memblock memblock_setclr_flag(phys_addr_t base,
> r->flags &= ~flag;
> }
>
> - memblock_merge_regions(type);
> + memblock_merge_regions(type, start_rgn, end_rgn);
> return 0;
> }
>
> @@ -1275,7 +1288,7 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
> for (i = start_rgn; i < end_rgn; i++)
> memblock_set_region_node(&type->regions[i], nid);
>
> - memblock_merge_regions(type);
> + memblock_merge_regions(type, start_rgn, end_rgn);
> #endif
> return 0;
> }
Sincerely yours,
Peng.
next prev parent reply other threads:[~2023-01-29 9:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-29 9:00 [PATCH v2 0/2] Some small improvements for memblock Peng Zhang
2023-01-29 9:00 ` [PATCH v2 1/2] memblock: Make a boundary tighter in memblock_add_range() Peng Zhang
2023-01-29 9:00 ` [PATCH v2 2/2] memblock: Avoid useless checks in memblock_merge_regions() Peng Zhang
2023-01-29 9:14 ` Peng Zhang [this message]
2023-01-31 14:12 ` [PATCH v2 0/2] Some small improvements for memblock Mike Rapoport
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