From: Pavel Machek <pavel@ucw.cz>
To: bjorn.topel@intel.com, magnus.karlsson@intel.com,
jonathan.lemon@gmail.com, davem@davemloft.net, kuba@kernel.org,
ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org,
john.fastabend@gmail.com, netdev@vger.kernel.org,
trivial@kernel.org
Subject: [PATCH] net/xdp: use shift instead of 64 bit division
Date: Thu, 4 Jun 2020 23:42:59 +0200 [thread overview]
Message-ID: <20200604214259.GA10835@amd> (raw)
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64bit division is kind of expensive, and shift should do the job here.
Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
---
Now with patch. Sorry about that.
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 3889bd9aec46..d6c91a43a1ee 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -372,7 +372,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
if ((addr + size) < addr)
return -EINVAL;
- npgs = div_u64(size, PAGE_SIZE);
+ npgs = size >> PAGE_SHIFT;
if (npgs > U32_MAX)
return -EINVAL;
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next reply other threads:[~2020-06-04 21:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-04 21:42 Pavel Machek [this message]
2020-06-04 23:03 ` [PATCH] net/xdp: use shift instead of 64 bit division David Miller
-- strict thread matches above, loose matches on Subject: below --
2020-06-04 21:33 Pavel Machek
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