[PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[Xiang Gao]

From: gaoxiang17 <gaoxiang17@xiaomi.com>

[   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
[   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
[   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)

Signed-off-by: gaoxiang17 <gaoxiang17@xiaomi.com>
---
 mm/cma.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/mm/cma.c b/mm/cma.c
index 3e9724716bad..cceff3b6a79e 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
 	spin_unlock_irq(&cma->lock);
 }
 
+static unsigned long cma_get_used(struct cma *cma)
+{
+	unsigned long used;
+
+	spin_lock_irq(&cma->lock);
+	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
+	spin_unlock_irq(&cma->lock);
+
+	return (unsigned long)used << cma->order_per_bit;
+}
+
 /**
  * cma_alloc() - allocate pages from contiguous area
  * @cma:   Contiguous memory region for which the allocation is performed.
@@ -430,8 +441,8 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
 	if (!cma || !cma->count || !cma->bitmap)
 		return page;
 
-	pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
-		(void *)cma, cma->name, count, align);
+	pr_debug("%s(cma %p, name: %s, total count %lu, used count: %lu, request count %lu, align %d)\n", __func__,
+		(void *)cma, cma->name, cma->count, cma_get_used(cma), count, align);
 
 	if (!count)
 		return page;
-- 
2.34.1

Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[Andrew Morton]

On Wed, 18 Sep 2024 20:43:25 +0800 Xiang Gao <gxxa03070307@gmail.com> wrote:

> From: gaoxiang17 <gaoxiang17@xiaomi.com>
> 
> [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
> 

Providing before-and-after output would make the proposal more easily
understood.

> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
>  	spin_unlock_irq(&cma->lock);
>  }
>  
> +static unsigned long cma_get_used(struct cma *cma)
> +{
> +	unsigned long used;
> +
> +	spin_lock_irq(&cma->lock);
> +	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));

Is the (int) cast needed?

> +	spin_unlock_irq(&cma->lock);
> +
> +	return (unsigned long)used << cma->order_per_bit;

Is the (unsigned long) bast needed?

> +}
> +
>  /**
>   * cma_alloc() - allocate pages from contiguous area
>   * @cma:   Contiguous memory region for which the allocation is performed.
> @@ -430,8 +441,8 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
>  	if (!cma || !cma->count || !cma->bitmap)
>  		return page;
>  
> -	pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
> -		(void *)cma, cma->name, count, align);
> +	pr_debug("%s(cma %p, name: %s, total count %lu, used count: %lu, request count %lu, align %d)\n", __func__,
> +		(void *)cma, cma->name, cma->count, cma_get_used(cma), count, align);
>  
>  	if (!count)
>  		return page;
> -- 
> 2.34.1

答复: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[高翔]

[-- Attachment #1: Type: text/plain, Size: 4969 bytes --]

> [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
>


Above is the cma alloc during boot. The before-and-after context has nothing to do with cma alloc. Below is the log with before-and-after context added.


[   24.006605] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[   24.071644] Serial: AMBA driver
[   24.096063] arm-smmu-v3 9050000.smmuv3: ias 44-bit, oas 44-bit (features 0x00000305)
[   24.097989] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
[   24.104260] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
[   24.107504] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
[   24.140495] cacheinfo: Unable to detect cache hierarchy for CPU 0
[   24.484998] loop: module loaded
[   24.536152] virtio_blk virtio0: [vda] 4194304 512-byte logical blocks (2.15 GB/2.00 GiB)


> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
>       spin_unlock_irq(&cma->lock);
>  }
>
> +static unsigned long cma_get_used(struct cma *cma)
> +{
> +     unsigned long used;
> +
> +     spin_lock_irq(&cma->lock);
> +     used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));

Is the (int) cast needed?
No need here.

> +     spin_unlock_irq(&cma->lock);
> +
> +     return (unsigned long)used << cma->order_per_bit;

Is the (unsigned long) cast needed?
No need here.




________________________________
发件人: Andrew Morton <akpm@linux-foundation.org>
发送时间: 2024年9月25日 8:27:19
收件人: Xiang Gao
抄送: linux-mm@kvack.org; linux-kernel@vger.kernel.org; 高翔
主题: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈

On Wed, 18 Sep 2024 20:43:25 +0800 Xiang Gao <gxxa03070307@gmail.com> wrote:

> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>
> [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
>

Providing before-and-after output would make the proposal more easily
understood.

> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
>       spin_unlock_irq(&cma->lock);
>  }
>
> +static unsigned long cma_get_used(struct cma *cma)
> +{
> +     unsigned long used;
> +
> +     spin_lock_irq(&cma->lock);
> +     used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));

Is the (int) cast needed?

> +     spin_unlock_irq(&cma->lock);
> +
> +     return (unsigned long)used << cma->order_per_bit;

Is the (unsigned long) bast needed?

> +}
> +
>  /**
>   * cma_alloc() - allocate pages from contiguous area
>   * @cma:   Contiguous memory region for which the allocation is performed.
> @@ -430,8 +441,8 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
>       if (!cma || !cma->count || !cma->bitmap)
>               return page;
>
> -     pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
> -             (void *)cma, cma->name, count, align);
> +     pr_debug("%s(cma %p, name: %s, total count %lu, used count: %lu, request count %lu, align %d)\n", __func__,
> +             (void *)cma, cma->name, cma->count, cma_get_used(cma), count, align);
>
>       if (!count)
>               return page;
> --
> 2.34.1
#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#

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Re: 答复: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[Andrew Morton]

On Wed, 25 Sep 2024 12:00:56 +0000 高翔 <gaoxiang17@xiaomi.com> wrote:

> > [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> > [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> > [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
> >
> 
> 
> Above is the cma alloc during boot. The before-and-after context has nothing to do with cma alloc. Below is the log with before-and-after context added.
> 
> 
> [   24.006605] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
> [   24.071644] Serial: AMBA driver
> [   24.096063] arm-smmu-v3 9050000.smmuv3: ias 44-bit, oas 44-bit (features 0x00000305)
> [   24.097989] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.104260] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.107504] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
> [   24.140495] cacheinfo: Unable to detect cache hierarchy for CPU 0
> [   24.484998] loop: module loaded
> [   24.536152] virtio_blk virtio0: [vda] 4194304 512-byte logical blocks (2.15 GB/2.00 GiB)

What I mean is to paste the messages before the patch and to paste the
messages after the patch.  So readers can easily see what changed.

答复: 答复: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[高翔]

[-- Attachment #1: Type: text/plain, Size: 3465 bytes --]

I see.

before:
[   24.407814] cma: cma_alloc(cma (____ptrval____), name: reserved, count 1, align 0)
[   24.413397] cma: cma_alloc(cma (____ptrval____), name: reserved, count 1, align 0)
[   24.415886] cma: cma_alloc(cma (____ptrval____), name: reserved, count 1, align 0)

after:
[   24.097989] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
[   24.104260] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
[   24.107504] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)


________________________________
发件人: Andrew Morton <akpm@linux-foundation.org>
发送时间: 2024年9月25日 21:15:36
收件人: 高翔
抄送: Xiang Gao; linux-mm@kvack.org; linux-kernel@vger.kernel.org
主题: Re: 答复: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈

On Wed, 25 Sep 2024 12:00:56 +0000 高翔 <gaoxiang17@xiaomi.com> wrote:

> > [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> > [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> > [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
> >
>
>
> Above is the cma alloc during boot. The before-and-after context has nothing to do with cma alloc. Below is the log with before-and-after context added.
>
>
> [   24.006605] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
> [   24.071644] Serial: AMBA driver
> [   24.096063] arm-smmu-v3 9050000.smmuv3: ias 44-bit, oas 44-bit (features 0x00000305)
> [   24.097989] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.104260] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.107504] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
> [   24.140495] cacheinfo: Unable to detect cache hierarchy for CPU 0
> [   24.484998] loop: module loaded
> [   24.536152] virtio_blk virtio0: [vda] 4194304 512-byte logical blocks (2.15 GB/2.00 GiB)

What I mean is to paste the messages before the patch and to paste the
messages after the patch.  So readers can easily see what changed.

#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#

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答复: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[高翔]

[-- Attachment #1: Type: text/plain, Size: 4965 bytes --]

> [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
>

Above is the cma alloc during boot. The before-and-after context has nothing to do with cma alloc. Below is the log with before-and-after context added.

[   24.006605] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[   24.071644] Serial: AMBA driver
[   24.096063] arm-smmu-v3 9050000.smmuv3: ias 44-bit, oas 44-bit (features 0x00000305)
[   24.097989] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
[   24.104260] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
[   24.107504] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
[   24.140495] cacheinfo: Unable to detect cache hierarchy for CPU 0
[   24.484998] loop: module loaded
[   24.536152] virtio_blk virtio0: [vda] 4194304 512-byte logical blocks (2.15 GB/2.00 GiB)




> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
>       spin_unlock_irq(&cma->lock);
>  }
>
> +static unsigned long cma_get_used(struct cma *cma)
> +{
> +     unsigned long used;
> +
> +     spin_lock_irq(&cma->lock);
> +     used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));

Is the (int) cast needed?
No need here.

> +     spin_unlock_irq(&cma->lock);
> +
> +     return (unsigned long)used << cma->order_per_bit;

Is the (unsigned long) cast needed?
No need here.


________________________________
发件人: Andrew Morton <akpm@linux-foundation.org>
发送时间: 2024年9月25日 8:27:19
收件人: Xiang Gao
抄送: linux-mm@kvack.org; linux-kernel@vger.kernel.org; 高翔
主题: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈

On Wed, 18 Sep 2024 20:43:25 +0800 Xiang Gao <gxxa03070307@gmail.com> wrote:

> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>
> [   24.225125] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 64, request count 1, align 0)
> [   24.231963] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 65, request count 1, align 0)
> [   24.235712] cma: cma_alloc(cma (____ptrval____), name: reserved, total count 16384, used count: 66, request count 1, align 0)
>

Providing before-and-after output would make the proposal more easily
understood.

> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
>       spin_unlock_irq(&cma->lock);
>  }
>
> +static unsigned long cma_get_used(struct cma *cma)
> +{
> +     unsigned long used;
> +
> +     spin_lock_irq(&cma->lock);
> +     used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));

Is the (int) cast needed?

> +     spin_unlock_irq(&cma->lock);
> +
> +     return (unsigned long)used << cma->order_per_bit;

Is the (unsigned long) bast needed?

> +}
> +
>  /**
>   * cma_alloc() - allocate pages from contiguous area
>   * @cma:   Contiguous memory region for which the allocation is performed.
> @@ -430,8 +441,8 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
>       if (!cma || !cma->count || !cma->bitmap)
>               return page;
>
> -     pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
> -             (void *)cma, cma->name, count, align);
> +     pr_debug("%s(cma %p, name: %s, total count %lu, used count: %lu, request count %lu, align %d)\n", __func__,
> +             (void *)cma, cma->name, cma->count, cma_get_used(cma), count, align);
>
>       if (!count)
>               return page;
> --
> 2.34.1
#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#

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Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[David Hildenbrand]

On 18.09.24 14:43, Xiang Gao wrote:
> From: gaoxiang17 <gaoxiang17@xiaomi.com>
> 

Please move some of $subject into $description, to make it shorter.

Maybe use the subject:

"mm/cma: print total and used count in cma_alloc()"


-- 
Cheers,

David / dhildenb

答复: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[高翔]

[-- Attachment #1: Type: text/plain, Size: 754 bytes --]

okay
________________________________
发件人: David Hildenbrand <david@redhat.com>
发送时间: 2024年9月26日 18:52:40
收件人: Xiang Gao; akpm@linux-foundation.org
抄送: linux-mm@kvack.org; linux-kernel@vger.kernel.org; 高翔
主题: [External Mail]Re: [PATCH] mm/cma.c: To better understand cma area during debugging, add total and used count logs to in cma_alloc

[外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈

On 18.09.24 14:43, Xiang Gao wrote:
> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>

Please move some of $subject into $description, to make it shorter.

Maybe use the subject:

"mm/cma: print total and used count in cma_alloc()"


--
Cheers,

David / dhildenb


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