linux-kernel - [PATCH v2 32/70] arch/powerpc: Optimize cell spu task sync.

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Date:   Tue, 12 Jan 2021 11:12:02 -0500
From:   "Liam R. Howlett" <Liam.Howlett@...cle.com>
To:     maple-tree@...ts.infradead.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Cc:     Andrew Morton <akpm@...gle.com>, Song Liu <songliubraving@...com>,
        Davidlohr Bueso <dave@...olabs.net>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Jerome Glisse <jglisse@...hat.com>,
        David Rientjes <rientjes@...gle.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Rik van Riel <riel@...riel.com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH v2 32/70] arch/powerpc: Optimize cell spu task sync.

Use the vma api to look up the spu reference instead of walking the linked list.

Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
 arch/powerpc/oprofile/cell/spu_task_sync.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/oprofile/cell/spu_task_sync.c b/arch/powerpc/oprofile/cell/spu_task_sync.c
index 489f993100d56..47b4d4e9b628d 100644
--- a/arch/powerpc/oprofile/cell/spu_task_sync.c
+++ b/arch/powerpc/oprofile/cell/spu_task_sync.c
@@ -333,19 +333,17 @@ get_exec_dcookie_and_offset(struct spu *spu, unsigned int *offsetp,
 	}
 
 	mmap_read_lock(mm);
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
-		if (vma->vm_start > spu_ref || vma->vm_end <= spu_ref)
-			continue;
-		my_offset = spu_ref - vma->vm_start;
-		if (!vma->vm_file)
-			goto fail_no_image_cookie;
-
-		pr_debug("Found spu ELF at %X(object-id:%lx) for file %pD\n",
-			 my_offset, spu_ref, vma->vm_file);
-		*offsetp = my_offset;
-		break;
-	}
+	vma = find_vma_intersection(mm, spu_ref, spu_ref + 1);
+	if (!vma)
+		goto fail_no_image_cookie;
+
+	my_offset = spu_ref - vma->vm_start;
+	if (!vma->vm_file)
+		goto fail_no_image_cookie;
 
+	pr_debug("Found spu ELF at %X(object-id:%lx) for file %pD\n",
+		 my_offset, spu_ref, vma->vm_file);
+	*offsetp = my_offset;
 	*spu_bin_dcookie = fast_get_dcookie(&vma->vm_file->f_path);
 	pr_debug("got dcookie for %pD\n", vma->vm_file);
 
-- 
2.28.0