+ dmapool-dont-memset-on-free-twice.patch added to mm-unstable branch

+ dmapool-dont-memset-on-free-twice.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: dmapool: don't memset on free twice
has been added to the -mm mm-unstable branch.  Its filename is
     dmapool-dont-memset-on-free-twice.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/dmapool-dont-memset-on-free-twice.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Keith Busch <kbusch@kernel.org>
Subject: dmapool: don't memset on free twice
Date: Thu, 26 Jan 2023 13:51:23 -0800

If debug is enabled, dmapool will poison the range, so no need to clear it
to 0 immediately before writing over it.

Link: https://lkml.kernel.org/r/20230126215125.4069751-11-kbusch@meta.com
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/dmapool.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/dmapool.c~dmapool-dont-memset-on-free-twice
+++ a/mm/dmapool.c
@@ -160,6 +160,8 @@ static void pool_check_block(struct dma_
 static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,
 			  void *vaddr, dma_addr_t dma)
 {
+	if (want_init_on_free())
+		memset(vaddr, 0, pool->size);
 	return false;
 }
 
@@ -441,8 +443,6 @@ void dma_pool_free(struct dma_pool *pool
 		return;
 	}
 
-	if (want_init_on_free())
-		memset(vaddr, 0, pool->size);
 	if (pool_page_err(pool, page, vaddr, dma)) {
 		spin_unlock_irqrestore(&pool->lock, flags);
 		return;
_

Patches currently in -mm which might be from kbusch@kernel.org are

dmapool-add-alloc-free-performance-test.patch
dmapool-move-debug-code-to-own-functions.patch
dmapool-rearrange-page-alloc-failure-handling.patch
dmapool-consolidate-page-initialization.patch
dmapool-simplify-freeing.patch
dmapool-dont-memset-on-free-twice.patch
dmapool-link-blocks-across-pages.patch
dmapool-create-destroy-cleanup.patch