linux-kernel - Re: [RESEND PATCH v7 04/10] mm: thp: Support allocation of anonymous small-sized THP

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Date:   Mon, 27 Nov 2023 16:41:35 +1300
From:   Barry Song <21cnbao@...il.com>
To:     ryan.roberts@....com
Cc:     akpm@...ux-foundation.org, anshuman.khandual@....com,
        catalin.marinas@....com, david@...hat.com, fengwei.yin@...el.com,
        hughd@...gle.com, itaru.kitayama@...il.com, jhubbard@...dia.com,
        kirill.shutemov@...ux.intel.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, mcgrof@...nel.org, rientjes@...gle.com,
        shy828301@...il.com, vbabka@...e.cz, wangkefeng.wang@...wei.com,
        willy@...radead.org, ying.huang@...el.com, yuzhao@...gle.com,
        ziy@...dia.com
Subject: Re: [RESEND PATCH v7 04/10] mm: thp: Support allocation of anonymous small-sized THP

> +	if ((nr_pages == 1 && vmf_pte_changed(vmf)) ||
> +	    (nr_pages  > 1 && !pte_range_none(vmf->pte, nr_pages))) {
> +		for (i = 0; i < nr_pages; i++)
> +			update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
>  		goto release;
>  	}

Hi Ryan,
what has stopped nr_pages == 1 from using !pte_range_none(vmf->pte, 1)
directly, then the code can become,
+	if (!pte_range_none(vmf->pte, nr_pages)) {
+		for (i = 0; i < nr_pages; i++)
+			update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
 		goto release;
 	}

for both 1 and > 1 cases?

Thanks
Barry