| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <485f47cc-669e-49b2-827e-bf5ab84b28e3@huawei.com>
Date: Tue, 8 Apr 2025 17:53:42 +0800
From: Qinxin Xia <xiaqinxin@...wei.com>
To: Barry Song <21cnbao@...il.com>
CC: <yangyicong@...wei.com>, <hch@....de>, <iommu@...ts.linux.dev>,
<jonathan.cameron@...wei.com>, <prime.zeng@...wei.com>,
<fanghao11@...wei.com>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/3] dma-mapping: benchmark: add support for dma_map_sg
在 2025/4/7 13:50, Barry Song 写道:
> On Wed, Feb 12, 2025 at 3:27 PM Qinxin Xia <xiaqinxin@...wei.com> wrote:
>> Support for dma scatter-gather mapping and is intended for testing
>> mapping performance. It achieves by introducing the dma_sg_map_param
>> structure and related functions, which enable the implementation of
>> scatter-gather mapping preparation, mapping, and unmapping operations.
>> Additionally, the dma_map_benchmark_ops array is updated to include
>> operations for scatter-gather mapping. This commit aims to provide
>> a wider range of mapping performance test to cater to different scenarios.
>>
>> Signed-off-by: Qinxin Xia <xiaqinxin@...wei.com>
>> ---
>> include/linux/map_benchmark.h | 1 +
>> kernel/dma/map_benchmark.c | 102 ++++++++++++++++++++++++++++++++++
>> 2 files changed, 103 insertions(+)
>>
>> diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
>> index 054db02a03a7..a9c1a104ba4f 100644
>> --- a/include/linux/map_benchmark.h
>> +++ b/include/linux/map_benchmark.h
>> @@ -17,6 +17,7 @@
>>
>> enum {
>> DMA_MAP_SINGLE_MODE,
>> + DMA_MAP_SG_MODE,
>> DMA_MAP_MODE_MAX
>> };
>>
>> diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
>> index d8ec0ce058d8..b5828eeb3db7 100644
>> --- a/kernel/dma/map_benchmark.c
>> +++ b/kernel/dma/map_benchmark.c
>> @@ -17,6 +17,7 @@
>> #include <linux/module.h>
>> #include <linux/pci.h>
>> #include <linux/platform_device.h>
>> +#include <linux/scatterlist.h>
>> #include <linux/slab.h>
>> #include <linux/timekeeping.h>
>>
>> @@ -111,8 +112,109 @@ static struct map_benchmark_ops dma_single_map_benchmark_ops = {
>> .do_unmap = dma_single_map_benchmark_do_unmap,
>> };
>>
>> +struct dma_sg_map_param {
>> + struct sg_table sgt;
>> + struct device *dev;
>> + void **buf;
>> + u32 npages;
>> + u32 dma_dir;
>> +};
>> +
>> +static void *dma_sg_map_benchmark_prepare(struct map_benchmark_data *map)
>> +{
>> + struct scatterlist *sg;
>> + int i = 0;
>> +
>> + struct dma_sg_map_param *mparam __free(kfree) = kzalloc(sizeof(*mparam), GFP_KERNEL);
>> + if (!mparam)
>> + return NULL;
>> +
>> + mparam->npages = map->bparam.granule;
> Please add comments explaining that "granule" serves as nents in SG
> mode, and that each SG entry corresponds to a single page.
> Otherwise, in single mode, the granule represents what we map and
> unmap as a whole in a single operation.
> I mean, make the code below clearly express what you are doing:
>
> __u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
>
Okay, I'll add comments here in next version, thank you for your advice!
>> + mparam->dma_dir = map->bparam.dma_dir;
>> + mparam->dev = map->dev;
>> + mparam->buf = kmalloc_array(mparam->npages, sizeof(*mparam->buf),
>> + GFP_KERNEL);
>> + if (!mparam->buf)
>> + goto err1;
>> +
>> + if (sg_alloc_table(&mparam->sgt, mparam->npages, GFP_KERNEL))
>> + goto err2;
>> +
>> + for_each_sgtable_sg(&mparam->sgt, sg, i) {
>> + mparam->buf[i] = (void *)__get_free_page(GFP_KERNEL);
>> + if (!mparam->buf[i])
>> + goto err3;
>> +
>> + if (mparam->dma_dir != DMA_FROM_DEVICE)
>> + memset(mparam->buf[i], 0x66, PAGE_SIZE);
>> +
>> + sg_set_buf(sg, mparam->buf[i], PAGE_SIZE);
>> + }
>> +
>> + return_ptr(mparam);
>> +
>> +err3:
>> + while (i-- > 0)
>> + free_page((unsigned long)mparam->buf[i]);
>> +
>> + pr_err("dma_map_sg failed get free page on %s\n", dev_name(mparam->dev));
>> + sg_free_table(&mparam->sgt);
>> +err2:
>> + pr_err("dma_map_sg failed alloc sg table on %s\n", dev_name(mparam->dev));
>> + kfree(mparam->buf);
>> +err1:
>> + pr_err("dma_map_sg failed alloc mparam buf on %s\n", dev_name(mparam->dev));
>> + return NULL;
> I assume allocation failures will already trigger their own warnings, so your
> pr_err isn't necessary. BTW, please replace err1, err2, err3 with something
> meaningful.
Okay, I'll delete these unnecessary prints and make the label changes
more meaningful in the next version.
>> +}
>> +
>> +static void dma_sg_map_benchmark_unprepare(void *arg)
>> +{
>> + struct dma_sg_map_param *mparam = arg;
>> + int i;
>> +
>> + for (i = 0; i < mparam->npages; i++)
>> + free_page((unsigned long)mparam->buf[i]);
>> +
>> + sg_free_table(&mparam->sgt);
>> +
>> + kfree(mparam->buf);
>> + kfree(mparam);
>> +}
>> +
>> +static int dma_sg_map_benchmark_do_map(void *arg)
>> +{
>> + struct dma_sg_map_param *mparam = arg;
>> +
>> + int sg_mapped = dma_map_sg(mparam->dev, mparam->sgt.sgl,
>> + mparam->npages, mparam->dma_dir);
>> + if (!sg_mapped) {
>> + pr_err("dma_map_sg failed on %s\n", dev_name(mparam->dev));
>> + return -ENOMEM;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int dma_sg_map_benchmark_do_unmap(void *arg)
> void
Initially for future expansion considerations, but I think, as you
suggested, we could make it 'void' first.
>> +{
>> + struct dma_sg_map_param *mparam = arg;
>> +
>> + dma_unmap_sg(mparam->dev, mparam->sgt.sgl, mparam->npages,
>> + mparam->dma_dir);
>> +
>> + return 0;
> drop it.
Okay, I'll fix it in the next version.
>> +}
>> +
>> +static struct map_benchmark_ops dma_sg_map_benchmark_ops = {
>> + .prepare = dma_sg_map_benchmark_prepare,
>> + .unprepare = dma_sg_map_benchmark_unprepare,
>> + .do_map = dma_sg_map_benchmark_do_map,
>> + .do_unmap = dma_sg_map_benchmark_do_unmap,
>> +};
>> +
>> static struct map_benchmark_ops *dma_map_benchmark_ops[DMA_MAP_MODE_MAX] = {
>> [DMA_MAP_SINGLE_MODE] = &dma_single_map_benchmark_ops,
>> + [DMA_MAP_SG_MODE] = &dma_sg_map_benchmark_ops,
>> };
>>
>> static int map_benchmark_thread(void *data)
>> --
>> 2.33.0
>>
> Thanks
> Barry
Powered by blists - more mailing lists