Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
On Wed, 2015-07-29 at 20:27 -0500, Zhao Qiang-B45475 wrote: On Thu, 2015-07-30 at 5:21, Scott Wood wrote: -Original Message- From: Wood Scott-B07421 Sent: Thursday, July 30, 2015 12:19 AM To: Zhao Qiang-B45475 Cc: lau...@codeaurora.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; a...@linux-foundation.org; o...@lixom.net; catalin.mari...@arm.com; Xie Xiaobo-R63061 Subject: Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc On Tue, 2015-07-28 at 00:32 -0500, Zhao Qiang-B45475 wrote: On Tue, 2015-07-28 at 5:21, Scott Wood wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 28, 2015 5:21 AM To: Zhao Qiang-B45475 Cc: lau...@codeaurora.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; a...@linux-foundation.org; o...@lixom.net; catalin.mari...@arm.com; Xie Xiaobo-R63061 Subject: Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc On Mon, 2015-07-27 at 17:57 +0800, Zhao Qiang wrote: Where's the part that adds the ability to pass in data to each allocation call, as per the previous discussion? You means to use gen_pool_alloc_data()? Yes. Previously you said that the format of data is algorithm-specific, So I think it is better to handle data in algorithm function. It is a channel for communication from the API caller to the algorithm. If you still prefer gen_pool_alloc_data(), I will modify it. But there still are details I want to confirm with you. 1. If use gen_pool_alloc_data(), should I pass data as a parameter? Yes. 2. Should I count align_mask in gen_pool_alloc_data(), meanwhile, add a align_mask to data as a member? gen_pool_alloc_data() should just pass data to the algorithm. The algorithm should calculate align_mask based on align. I don't think exposing align_mask to API users would be very friendly. If calculate align_mask in algorithm, I need to get pool-min_alloc_order in algorithm, Like: order = data-pool-min_alloc_order; align_mask = ((data-align + (1UL order) - 1) order) - 1; so I add pool to structure data as a member. Is there any other better idea? Pass pool as a parameter to the algorithm. -Scott ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
On Tue, 2015-07-28 at 00:32 -0500, Zhao Qiang-B45475 wrote: On Tue, 2015-07-28 at 5:21, Scott Wood wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 28, 2015 5:21 AM To: Zhao Qiang-B45475 Cc: lau...@codeaurora.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; a...@linux-foundation.org; o...@lixom.net; catalin.mari...@arm.com; Xie Xiaobo-R63061 Subject: Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc On Mon, 2015-07-27 at 17:57 +0800, Zhao Qiang wrote: Where's the part that adds the ability to pass in data to each allocation call, as per the previous discussion? You means to use gen_pool_alloc_data()? Yes. Previously you said that the format of data is algorithm-specific, So I think it is better to handle data in algorithm function. It is a channel for communication from the API caller to the algorithm. If you still prefer gen_pool_alloc_data(), I will modify it. But there still are details I want to confirm with you. 1. If use gen_pool_alloc_data(), should I pass data as a parameter? Yes. 2. Should I count align_mask in gen_pool_alloc_data(), meanwhile, add a align_mask to data as a member? gen_pool_alloc_data() should just pass data to the algorithm. The algorithm should calculate align_mask based on align. I don't think exposing align_mask to API users would be very friendly. 3. where to define the data, in genalloc.h or caller layer? Same place as where the algorithm function is declared. -Scott ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
RE: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
On Thu, 2015-07-30 at 5:21, Scott Wood wrote: -Original Message- From: Wood Scott-B07421 Sent: Thursday, July 30, 2015 12:19 AM To: Zhao Qiang-B45475 Cc: lau...@codeaurora.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; a...@linux-foundation.org; o...@lixom.net; catalin.mari...@arm.com; Xie Xiaobo-R63061 Subject: Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc On Tue, 2015-07-28 at 00:32 -0500, Zhao Qiang-B45475 wrote: On Tue, 2015-07-28 at 5:21, Scott Wood wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 28, 2015 5:21 AM To: Zhao Qiang-B45475 Cc: lau...@codeaurora.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; a...@linux-foundation.org; o...@lixom.net; catalin.mari...@arm.com; Xie Xiaobo-R63061 Subject: Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc On Mon, 2015-07-27 at 17:57 +0800, Zhao Qiang wrote: Where's the part that adds the ability to pass in data to each allocation call, as per the previous discussion? You means to use gen_pool_alloc_data()? Yes. Previously you said that the format of data is algorithm-specific, So I think it is better to handle data in algorithm function. It is a channel for communication from the API caller to the algorithm. If you still prefer gen_pool_alloc_data(), I will modify it. But there still are details I want to confirm with you. 1. If use gen_pool_alloc_data(), should I pass data as a parameter? Yes. 2. Should I count align_mask in gen_pool_alloc_data(), meanwhile, add a align_mask to data as a member? gen_pool_alloc_data() should just pass data to the algorithm. The algorithm should calculate align_mask based on align. I don't think exposing align_mask to API users would be very friendly. If calculate align_mask in algorithm, I need to get pool-min_alloc_order in algorithm, Like: order = data-pool-min_alloc_order; align_mask = ((data-align + (1UL order) - 1) order) - 1; so I add pool to structure data as a member. Is there any other better idea? 3. where to define the data, in genalloc.h or caller layer? Same place as where the algorithm function is declared. -Scott -Zhao Qiang ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
RE: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
On Tue, 2015-07-28 at 5:21, Scott Wood wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 28, 2015 5:21 AM To: Zhao Qiang-B45475 Cc: lau...@codeaurora.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; a...@linux-foundation.org; o...@lixom.net; catalin.mari...@arm.com; Xie Xiaobo-R63061 Subject: Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc On Mon, 2015-07-27 at 17:57 +0800, Zhao Qiang wrote: Where's the part that adds the ability to pass in data to each allocation call, as per the previous discussion? You means to use gen_pool_alloc_data()? Previously you said that the format of data is algorithm-specific, So I think it is better to handle data in algorithm function. If you still prefer gen_pool_alloc_data(), I will modify it. But there still are details I want to confirm with you. 1. If use gen_pool_alloc_data(), should I pass data as a parameter? 2. Should I count align_mask in gen_pool_alloc_data(), meanwhile, add a align_mask to data as a member? 3. where to define the data, in genalloc.h or caller layer? -Scott ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
Hello Zhao,
On 27.07.2015 12:57, Zhao Qiang wrote:
Bytes alignment is required to manage some special ram,
so add gen_pool_first_fit_align to genalloc.
User should define data structure
struct data {
int align;
struct gen_pool *pool;
}
align is the number of bytes alignment,
pool points to gen_pool which include data.
Signed-off-by: Zhao Qiang qiang.z...@freescale.com
---
*v2:
changes:
title has been modified, original patch link:
http://patchwork.ozlabs.org/patch/493297/
original patch add a func gen_pool_alloc_align,
then pass alignment to it as an parameter.
after discussing with lauraa and scott, they recommend
to pass alignment as part of data based on
commit message for ca279cf1065fb689abea1dc7d8c11787729bb185 which adds data:
As I can't predict all the possible requirements/needs for all allocation
uses cases, I add a free field 'void *data' to pass any needed
information to the allocation function. For example 'data' could be used
to handle a structure where you store the alignment, the expected memory
bank, the requester device, or any information that could influence the
allocation algorithm.
include/linux/genalloc.h | 4
lib/genalloc.c | 25 +
2 files changed, 29 insertions(+)
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 1ccaab4..b85d0f8 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -110,6 +110,10 @@ extern void gen_pool_set_algo(struct gen_pool *pool,
genpool_algo_t algo,
extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long
size,
unsigned long start, unsigned int nr, void *data);
+extern unsigned long gen_pool_first_fit_align(unsigned long *map,
+ unsigned long size, unsigned long start, unsigned int nr,
+ void *data);
+
extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,
unsigned long size, unsigned long start, unsigned int nr,
void *data);
diff --git a/lib/genalloc.c b/lib/genalloc.c
index d214866..e6608cd 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -509,6 +509,31 @@ unsigned long gen_pool_first_fit(unsigned long *map,
unsigned long size,
EXPORT_SYMBOL(gen_pool_first_fit);
/**
+ * gen_pool_first_fit_align - find the first available region
+ * of memory matching the size requirement (no alignment constraint)
no alignment constraint?
+ * @map: The address to base the search on
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @data: additional data - unused
unused?
+ */
+unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long
size,
+ unsigned long start, unsigned int nr, void *data)
+{
+ unsigned long align_mask;
+ int order;
+
+ if (data data-pool) {
data type is (void *), missing cast?
+ order = data-pool-min_alloc_order;
+ align_mask = ((data-align + (1UL order) - 1) order) - 1;
+ } else {
+ pr_err(no data or data-pool\n);
+ }
+ return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
You may end up in a situation, when align_mask is undefined, I believe
bitmap_find_next_zero_area() should not be called on error path.
+}
+EXPORT_SYMBOL(gen_pool_first_fit_algin);
+
+/**
* gen_pool_first_fit_order_align - find the first available region
* of memory matching the size requirement. The region will be aligned
* to the order of the size specified.
--
With best wishes,
Vladimir
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Re: [RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
On Mon, 2015-07-27 at 17:57 +0800, Zhao Qiang wrote:
diff --git a/lib/genalloc.c b/lib/genalloc.c
index d214866..e6608cd 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -509,6 +509,31 @@ unsigned long gen_pool_first_fit(unsigned long *map,
unsigned long size,
EXPORT_SYMBOL(gen_pool_first_fit);
/**
+ * gen_pool_first_fit_align - find the first available region
+ * of memory matching the size requirement (no alignment constraint)
+ * @map: The address to base the search on
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @data: additional data - unused
+ */
+unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long
size,
+ unsigned long start, unsigned int nr, void *data)
+{
+ unsigned long align_mask;
+ int order;
+
+ if (data data-pool) {
There is no way that this compiles. You can't dereference a void pointer.
Please test your code before submitting, even for an RFC.
+ order = data-pool-min_alloc_order;
I don't think pool belongs in data. It's fundamental enough that, if a
pointer to pool is needed, it should be an argument to the algorithm.
+ align_mask = ((data-align + (1UL order) - 1) order) - 1;
+ } else {
+ pr_err(no data or data-pool\n);
+ }
This is way too vague and unobtrusive of an error message, and also not rate-
limited, etc. I wouldn't bother checking at all. Just let it crash on the
developer's machine if they use this without passing in data.
Where's the part that adds the ability to pass in data to each allocation
call, as per the previous discussion?
-Scott
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[RFC v2] genalloc:add an gen_pool_first_fit_align algo to genalloc
Bytes alignment is required to manage some special ram,
so add gen_pool_first_fit_align to genalloc.
User should define data structure
struct data {
int align;
struct gen_pool *pool;
}
align is the number of bytes alignment,
pool points to gen_pool which include data.
Signed-off-by: Zhao Qiang qiang.z...@freescale.com
---
*v2:
changes:
title has been modified, original patch link:
http://patchwork.ozlabs.org/patch/493297/
original patch add a func gen_pool_alloc_align,
then pass alignment to it as an parameter.
after discussing with lauraa and scott, they recommend
to pass alignment as part of data based on
commit message for ca279cf1065fb689abea1dc7d8c11787729bb185 which adds data:
As I can't predict all the possible requirements/needs for all allocation
uses cases, I add a free field 'void *data' to pass any needed
information to the allocation function. For example 'data' could be used
to handle a structure where you store the alignment, the expected memory
bank, the requester device, or any information that could influence the
allocation algorithm.
include/linux/genalloc.h | 4
lib/genalloc.c | 25 +
2 files changed, 29 insertions(+)
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 1ccaab4..b85d0f8 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -110,6 +110,10 @@ extern void gen_pool_set_algo(struct gen_pool *pool,
genpool_algo_t algo,
extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
unsigned long start, unsigned int nr, void *data);
+extern unsigned long gen_pool_first_fit_align(unsigned long *map,
+ unsigned long size, unsigned long start, unsigned int nr,
+ void *data);
+
extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,
unsigned long size, unsigned long start, unsigned int nr,
void *data);
diff --git a/lib/genalloc.c b/lib/genalloc.c
index d214866..e6608cd 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -509,6 +509,31 @@ unsigned long gen_pool_first_fit(unsigned long *map,
unsigned long size,
EXPORT_SYMBOL(gen_pool_first_fit);
/**
+ * gen_pool_first_fit_align - find the first available region
+ * of memory matching the size requirement (no alignment constraint)
+ * @map: The address to base the search on
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @data: additional data - unused
+ */
+unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
+ unsigned long start, unsigned int nr, void *data)
+{
+ unsigned long align_mask;
+ int order;
+
+ if (data data-pool) {
+ order = data-pool-min_alloc_order;
+ align_mask = ((data-align + (1UL order) - 1) order) - 1;
+ } else {
+ pr_err(no data or data-pool\n);
+ }
+ return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
+}
+EXPORT_SYMBOL(gen_pool_first_fit_algin);
+
+/**
* gen_pool_first_fit_order_align - find the first available region
* of memory matching the size requirement. The region will be aligned
* to the order of the size specified.
--
2.1.0.27.g96db324
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