From: Robin Murphy <robin.murphy@arm.com>
To: hch@lst.de, m.szyprowski@samsung.com
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] dma-mapping: Reduce dma_mapping_error() inline bloat
Date: Mon, 24 Jul 2017 18:29:27 +0100 [thread overview]
Message-ID: <6a23eacf6603e75e995f8720c24b54c4fc2926f5.1500917215.git.robin.murphy@arm.com> (raw)
Thanks to the nested inlining, all drivers correctly calling
dma_mapping_error() after a mapping a page or single buffer generate two
calls to get_arch_dma_ops() per callsite, which all adds up to a fair
old chunk of useless code, e.g. ~3KB for an arm64 defconfig plus extras:
text data bss dec hex filename
13051391 1503898 327768 14883057 e318f1 vmlinux.o.old
13050751 1503898 327768 14882417 e31671 vmlinux.o.new
Give the compiler a hand by making it clear we want the same ops.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
include/linux/dma-mapping.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 843ab866e0f4..239e53d12ee8 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -541,10 +541,11 @@ static inline void dma_free_noncoherent(struct device *dev, size_t size,
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
- debug_dma_mapping_error(dev, dma_addr);
+ const struct dma_map_ops *ops = get_dma_ops(dev);
- if (get_dma_ops(dev)->mapping_error)
- return get_dma_ops(dev)->mapping_error(dev, dma_addr);
+ debug_dma_mapping_error(dev, dma_addr);
+ if (ops->mapping_error)
+ return ops->mapping_error(dev, dma_addr);
return 0;
}
--
2.12.2.dirty
next reply other threads:[~2017-07-24 17:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20170724172940epcas4p4b06b8fd5c66a475e1f8be1361981a14b@epcas4p4.samsung.com>
2017-07-24 17:29 ` Robin Murphy [this message]
2017-08-01 7:58 ` [PATCH] dma-mapping: Reduce dma_mapping_error() inline bloat Marek Szyprowski
2017-08-25 14:56 ` Christoph Hellwig
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