From: David Rientjes <rientjes@google.com>
To: Christoph Hellwig <hch@lst.de>, Tom Lendacky <thomas.lendacky@amd.com>
Cc: "Singh, Brijesh" <brijesh.singh@amd.com>,
"Grimm, Jon" <jon.grimm@amd.com>, Joerg Roedel <joro@8bytes.org>,
baekhw@google.com,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Subject: [rfc 6/6] dma-remap: double the default DMA coherent pool size
Date: Sun, 1 Mar 2020 16:05:27 -0800 (PST) [thread overview]
Message-ID: <alpine.DEB.2.21.2003011538260.213582@chino.kir.corp.google.com> (raw)
In-Reply-To: <alpine.DEB.2.21.2003011535510.213582@chino.kir.corp.google.com>
When AMD memory encryption is enabled, some devices may used more than
256KB/sec from the atomic pools. Double the default size to make the
original size and expansion more appropriate.
This provides a slight optimization on initial expansion and is deemed
appropriate for all configs with CONFIG_DMA_REMAP enabled because of the
increased reliance on the atomic pools.
Alternatively, this could be done only when CONFIG_AMD_MEM_ENCRYPT is
enabled.
Signed-off-by: David Rientjes <rientjes@google.com>
---
kernel/dma/remap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -105,7 +105,7 @@ static struct gen_pool *atomic_pool __ro_after_init;
static struct gen_pool *atomic_pool_dma32 __ro_after_init;
static struct gen_pool *atomic_pool_normal __ro_after_init;
-#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
+#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_512K
static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;
/* Dynamic background expansion when the atomic pool is near capacity */
next prev parent reply other threads:[~2020-03-02 0:05 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-01 1:54 [rfc] dma-mapping: preallocate unencrypted DMA atomic pool David Rientjes
2020-01-06 17:34 ` Robin Murphy
2020-01-07 10:54 ` Christoph Hellwig
2020-01-07 19:57 ` David Rientjes
2020-01-09 14:31 ` Christoph Hellwig
2020-01-09 18:58 ` David Rientjes
2020-01-17 15:28 ` Tom Lendacky
2020-02-28 9:27 ` David Rientjes
2020-03-02 0:05 ` [rfc 0/6] unencrypted atomic DMA pools with dynamic expansion David Rientjes
2020-03-02 0:05 ` [rfc 1/6] dma-mapping: pass device to atomic allocation functions David Rientjes
2020-03-02 0:05 ` [rfc 2/6] dma-remap: add additional atomic pools to map to gfp mask David Rientjes
2020-03-05 15:42 ` Christoph Hellwig
2020-03-02 0:05 ` [rfc 3/6] dma-remap: wire up the atomic pools depending on " David Rientjes
2020-03-05 15:43 ` Christoph Hellwig
2020-03-02 0:05 ` [rfc 4/6] dma-remap: dynamically expanding atomic pools David Rientjes
2020-03-03 22:29 ` David Rientjes
2020-03-02 0:05 ` [rfc 5/6] dma-direct: atomic allocations must come from unencrypted pools David Rientjes
2020-03-05 15:44 ` Christoph Hellwig
2020-03-07 0:36 ` David Rientjes
2020-03-10 18:47 ` Christoph Hellwig
2020-03-02 0:05 ` David Rientjes [this message]
2020-03-05 15:45 ` [rfc 6/6] dma-remap: double the default DMA coherent pool size Christoph Hellwig
2020-04-08 21:21 ` [rfc v2 0/6] unencrypted atomic DMA pools with dynamic expansion David Rientjes
2020-04-08 21:21 ` [rfc v2 1/6] dma-remap: separate DMA atomic pools from direct remap code David Rientjes
2020-04-14 6:35 ` Christoph Hellwig
2020-04-08 21:21 ` [rfc v2 2/6] dma-pool: add additional coherent pools to map to gfp mask David Rientjes
2020-04-08 21:21 ` [rfc v2 3/6] dma-pool: dynamically expanding atomic pools David Rientjes
2020-04-08 21:21 ` [rfc v2 4/6] dma-direct: atomic allocations must come from atomic coherent pools David Rientjes
2020-04-09 21:24 ` Tom Lendacky
2020-04-14 19:18 ` David Rientjes
2020-04-14 6:43 ` Christoph Hellwig
2020-04-14 19:20 ` David Rientjes
2020-04-08 21:21 ` [rfc v2 5/6] x86/mm: unencrypted non-blocking DMA allocations use " David Rientjes
2020-04-08 21:21 ` [rfc v2 6/6] dma-pool: scale the default DMA coherent pool size with memory capacity David Rientjes
[not found] ` <20200410145520.17864-1-hdanton@sina.com>
2020-04-10 19:37 ` [rfc v2 3/6] dma-pool: dynamically expanding atomic pools David Rientjes
2020-04-14 6:44 ` Christoph Hellwig
2020-04-14 19:23 ` David Rientjes
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