* [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm
@ 2020-08-20 2:16 Zhen Lei
2020-08-20 2:16 ` [PATCH v3 1/7] libnvdimm: fix memory leaks in of_pmem.c Zhen Lei
` (7 more replies)
0 siblings, 8 replies; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
v2 --> v3:
1. Fix spelling error of patch 1 subject: memmory --> memory
2. Add "Reviewed-by: Oliver O'Halloran <oohall@gmail.com>" into patch 1
3. Rewrite patch descriptions of Patch 1, 3, 4
4. Add 3 new trivial patches 5-7, I just found that yesterday.
5. Unify all "subsystem" names to "libnvdimm:"
v1 --> v2:
1. Add Fixes for Patch 1-2
2. Slightly change the subject and description of Patch 1
3. Add a new trivial Patch 4, I just found that yesterday.
v1:
I found a memleak when I learned the drivers/nvdimm code today. And I also
added a sanity check for priv->bus_desc.provider_name, because strdup()
maybe failed. Patch 3 is a trivial source code optimization.
Zhen Lei (7):
libnvdimm: fix memory leaks in of_pmem.c
libnvdimm: add sanity check for provider_name in
of_pmem_region_probe()
libnvdimm: simplify walk_to_nvdimm_bus()
libnvdimm: reduce an unnecessary if branch in nd_region_create()
libnvdimm: reduce an unnecessary if branch in nd_region_activate()
libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its
function
libnvdimm: slightly simplify available_slots_show()
drivers/nvdimm/bus.c | 7 +++----
drivers/nvdimm/dimm_devs.c | 5 ++---
drivers/nvdimm/of_pmem.c | 7 +++++++
drivers/nvdimm/region_devs.c | 13 ++++---------
4 files changed, 16 insertions(+), 16 deletions(-)
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 1/7] libnvdimm: fix memory leaks in of_pmem.c
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-20 2:16 ` [PATCH v3 2/7] libnvdimm: add sanity check for provider_name in of_pmem_region_probe() Zhen Lei
` (6 subsequent siblings)
7 siblings, 0 replies; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
Currently, in the last error path of of_pmem_region_probe() and in
of_pmem_region_remove(), free the memory allocated by kstrdup() is
missing. Add kfree(priv->bus_desc.provider_name) to fix it.
Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
---
drivers/nvdimm/of_pmem.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
index 10dbdcdfb9ce913..1292ffca7b2ecc0 100644
--- a/drivers/nvdimm/of_pmem.c
+++ b/drivers/nvdimm/of_pmem.c
@@ -36,6 +36,7 @@ static int of_pmem_region_probe(struct platform_device *pdev)
priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
if (!bus) {
+ kfree(priv->bus_desc.provider_name);
kfree(priv);
return -ENODEV;
}
@@ -83,6 +84,7 @@ static int of_pmem_region_remove(struct platform_device *pdev)
struct of_pmem_private *priv = platform_get_drvdata(pdev);
nvdimm_bus_unregister(priv->bus);
+ kfree(priv->bus_desc.provider_name);
kfree(priv);
return 0;
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 2/7] libnvdimm: add sanity check for provider_name in of_pmem_region_probe()
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
2020-08-20 2:16 ` [PATCH v3 1/7] libnvdimm: fix memory leaks in of_pmem.c Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-20 2:16 ` [PATCH v3 3/7] libnvdimm: simplify walk_to_nvdimm_bus() Zhen Lei
` (5 subsequent siblings)
7 siblings, 0 replies; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
kstrdup() may return NULL because of no memory, check it.
Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/nvdimm/of_pmem.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
index 1292ffca7b2ecc0..13c4c274ca6ea88 100644
--- a/drivers/nvdimm/of_pmem.c
+++ b/drivers/nvdimm/of_pmem.c
@@ -31,6 +31,11 @@ static int of_pmem_region_probe(struct platform_device *pdev)
return -ENOMEM;
priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
+ if (!priv->bus_desc.provider_name) {
+ kfree(priv);
+ return -ENOMEM;
+ }
+
priv->bus_desc.module = THIS_MODULE;
priv->bus_desc.of_node = np;
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 3/7] libnvdimm: simplify walk_to_nvdimm_bus()
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
2020-08-20 2:16 ` [PATCH v3 1/7] libnvdimm: fix memory leaks in of_pmem.c Zhen Lei
2020-08-20 2:16 ` [PATCH v3 2/7] libnvdimm: add sanity check for provider_name in of_pmem_region_probe() Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-20 2:16 ` [PATCH v3 4/7] libnvdimm: reduce an unnecessary if branch in nd_region_create() Zhen Lei
` (4 subsequent siblings)
7 siblings, 0 replies; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
Return as soon as nvdimm_bus device has been found, make us no need to
check "dev" or "!dev" in subsequent code.
No functional change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/nvdimm/bus.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 955265656b96c73..1d89114cb6ab93e 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -316,10 +316,9 @@ struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
for (dev = nd_dev; dev; dev = dev->parent)
if (is_nvdimm_bus(dev))
- break;
- dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
- if (dev)
- return to_nvdimm_bus(dev);
+ return to_nvdimm_bus(dev);
+
+ dev_WARN_ONCE(nd_dev, 1, "invalid dev, not on nd bus\n");
return NULL;
}
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 4/7] libnvdimm: reduce an unnecessary if branch in nd_region_create()
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
` (2 preceding siblings ...)
2020-08-20 2:16 ` [PATCH v3 3/7] libnvdimm: simplify walk_to_nvdimm_bus() Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-20 2:16 ` [PATCH v3 5/7] libnvdimm: reduce an unnecessary if branch in nd_region_activate() Zhen Lei
` (3 subsequent siblings)
7 siblings, 0 replies; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
if (ndr_desc->flush)
1) nd_region->flush = ndr_desc->flush;
else
2) nd_region->flush = NULL;
When entering the "else" branch, the value of ndr_desc->flush is NULL.
After replaced "NULL" with "ndr_desc->flush" at 2), we will find that
it becomes the same to 1).
So the above code snippet can be reduced to one statement:
nd_region->flush = ndr_desc->flush;
No functional change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/nvdimm/region_devs.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index ef23119db574663..7cf9c7d857909ce 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1131,10 +1131,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
nd_region->ndr_size = resource_size(ndr_desc->res);
nd_region->ndr_start = ndr_desc->res->start;
nd_region->align = default_align(nd_region);
- if (ndr_desc->flush)
- nd_region->flush = ndr_desc->flush;
- else
- nd_region->flush = NULL;
+ nd_region->flush = ndr_desc->flush;
nd_device_register(dev);
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 5/7] libnvdimm: reduce an unnecessary if branch in nd_region_activate()
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
` (3 preceding siblings ...)
2020-08-20 2:16 ` [PATCH v3 4/7] libnvdimm: reduce an unnecessary if branch in nd_region_create() Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-27 7:04 ` Leizhen (ThunderTown)
2020-08-20 2:16 ` [PATCH v3 6/7] libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its function Zhen Lei
` (2 subsequent siblings)
7 siblings, 1 reply; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
According to the original code logic:
if (!nvdimm->num_flush) {
flush_data_size += sizeof(void *);
//nvdimm->num_flush is zero now, add 1) have no side effects
} else {
flush_data_size += sizeof(void *);
1) flush_data_size += nvdimm->num_flush * sizeof(void *);
}
Obviously, the above code snippet can be reduced to one statement:
flush_data_size += (nvdimm->num_flush + 1) * sizeof(void *);
No functional change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/nvdimm/region_devs.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 7cf9c7d857909ce..49be115c9189eff 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -77,11 +77,8 @@ int nd_region_activate(struct nd_region *nd_region)
}
/* at least one null hint slot per-dimm for the "no-hint" case */
- flush_data_size += sizeof(void *);
+ flush_data_size += (nvdimm->num_flush + 1) * sizeof(void *);
num_flush = min_not_zero(num_flush, nvdimm->num_flush);
- if (!nvdimm->num_flush)
- continue;
- flush_data_size += nvdimm->num_flush * sizeof(void *);
}
nvdimm_bus_unlock(&nd_region->dev);
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 6/7] libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its function
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
` (4 preceding siblings ...)
2020-08-20 2:16 ` [PATCH v3 5/7] libnvdimm: reduce an unnecessary if branch in nd_region_activate() Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-20 11:05 ` Pankaj Gupta
2020-08-20 2:16 ` [PATCH v3 7/7] libnvdimm: slightly simplify available_slots_show() Zhen Lei
2020-08-27 6:35 ` [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Leizhen (ThunderTown)
7 siblings, 1 reply; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
Move EXPORT_SYMBOL_GPL(nvdimm_flush) close to nvdimm_flush(), currently
it's near to generic_nvdimm_flush().
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/nvdimm/region_devs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 49be115c9189eff..909bf03edb132cf 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1183,6 +1183,8 @@ int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
return rc;
}
+EXPORT_SYMBOL_GPL(nvdimm_flush);
+
/**
* nvdimm_flush - flush any posted write queues between the cpu and pmem media
* @nd_region: blk or interleaved pmem region
@@ -1214,7 +1216,6 @@ int generic_nvdimm_flush(struct nd_region *nd_region)
return 0;
}
-EXPORT_SYMBOL_GPL(nvdimm_flush);
/**
* nvdimm_has_flush - determine write flushing requirements
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 7/7] libnvdimm: slightly simplify available_slots_show()
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
` (5 preceding siblings ...)
2020-08-20 2:16 ` [PATCH v3 6/7] libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its function Zhen Lei
@ 2020-08-20 2:16 ` Zhen Lei
2020-08-21 12:56 ` Salih Agenter
2020-08-27 6:35 ` [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Leizhen (ThunderTown)
7 siblings, 1 reply; 12+ messages in thread
From: Zhen Lei @ 2020-08-20 2:16 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Cc: Zhen Lei
The type of "nfree" is u32, so "nfree - 1" can only be overflowed when
"nfree" is zero. Replace "if (nfree - 1 > nfree)" with "if (nfree == 0)"
seems more clear. And remove the assignment "nfree = 0", no need for it.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/nvdimm/dimm_devs.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 61374def515552f..bf7d0cdc147cb39 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -347,10 +347,9 @@ static ssize_t available_slots_show(struct device *dev,
nvdimm_bus_lock(dev);
nfree = nd_label_nfree(ndd);
- if (nfree - 1 > nfree) {
+ if (nfree == 0)
dev_WARN_ONCE(dev, 1, "we ate our last label?\n");
- nfree = 0;
- } else
+ else
nfree--;
rc = sprintf(buf, "%d\n", nfree);
nvdimm_bus_unlock(dev);
--
1.8.3
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v3 6/7] libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its function
2020-08-20 2:16 ` [PATCH v3 6/7] libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its function Zhen Lei
@ 2020-08-20 11:05 ` Pankaj Gupta
0 siblings, 0 replies; 12+ messages in thread
From: Pankaj Gupta @ 2020-08-20 11:05 UTC (permalink / raw)
To: Zhen Lei; +Cc: Markus Elfring, linux-nvdimm, linux-kernel
> Move EXPORT_SYMBOL_GPL(nvdimm_flush) close to nvdimm_flush(), currently
> it's near to generic_nvdimm_flush().
>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
> drivers/nvdimm/region_devs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
> index 49be115c9189eff..909bf03edb132cf 100644
> --- a/drivers/nvdimm/region_devs.c
> +++ b/drivers/nvdimm/region_devs.c
> @@ -1183,6 +1183,8 @@ int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
>
> return rc;
> }
> +EXPORT_SYMBOL_GPL(nvdimm_flush);
> +
> /**
> * nvdimm_flush - flush any posted write queues between the cpu and pmem media
> * @nd_region: blk or interleaved pmem region
> @@ -1214,7 +1216,6 @@ int generic_nvdimm_flush(struct nd_region *nd_region)
>
> return 0;
> }
> -EXPORT_SYMBOL_GPL(nvdimm_flush);
>
> /**
> * nvdimm_has_flush - determine write flushing requirements
> --
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
> 1.8.3
>
> _______________________________________________
> Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
> To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 7/7] libnvdimm: slightly simplify available_slots_show()
2020-08-20 2:16 ` [PATCH v3 7/7] libnvdimm: slightly simplify available_slots_show() Zhen Lei
@ 2020-08-21 12:56 ` Salih Agenter
0 siblings, 0 replies; 12+ messages in thread
From: Salih Agenter @ 2020-08-21 12:56 UTC (permalink / raw)
To: linux-nvdimm
https://www.agenter.com/how-to-earn
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
` (6 preceding siblings ...)
2020-08-20 2:16 ` [PATCH v3 7/7] libnvdimm: slightly simplify available_slots_show() Zhen Lei
@ 2020-08-27 6:35 ` Leizhen (ThunderTown)
7 siblings, 0 replies; 12+ messages in thread
From: Leizhen (ThunderTown) @ 2020-08-27 6:35 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
Hi all:
Any comment? I want to merge patches 1 and 2 into one, then send
other patches separately.
On 2020/8/20 10:16, Zhen Lei wrote:
> v2 --> v3:
> 1. Fix spelling error of patch 1 subject: memmory --> memory
> 2. Add "Reviewed-by: Oliver O'Halloran <oohall@gmail.com>" into patch 1
> 3. Rewrite patch descriptions of Patch 1, 3, 4
> 4. Add 3 new trivial patches 5-7, I just found that yesterday.
> 5. Unify all "subsystem" names to "libnvdimm:"
>
> v1 --> v2:
> 1. Add Fixes for Patch 1-2
> 2. Slightly change the subject and description of Patch 1
> 3. Add a new trivial Patch 4, I just found that yesterday.
>
> v1:
> I found a memleak when I learned the drivers/nvdimm code today. And I also
> added a sanity check for priv->bus_desc.provider_name, because strdup()
> maybe failed. Patch 3 is a trivial source code optimization.
>
>
> Zhen Lei (7):
> libnvdimm: fix memory leaks in of_pmem.c
> libnvdimm: add sanity check for provider_name in
> of_pmem_region_probe()
> libnvdimm: simplify walk_to_nvdimm_bus()
> libnvdimm: reduce an unnecessary if branch in nd_region_create()
> libnvdimm: reduce an unnecessary if branch in nd_region_activate()
> libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its
> function
> libnvdimm: slightly simplify available_slots_show()
>
> drivers/nvdimm/bus.c | 7 +++----
> drivers/nvdimm/dimm_devs.c | 5 ++---
> drivers/nvdimm/of_pmem.c | 7 +++++++
> drivers/nvdimm/region_devs.c | 13 ++++---------
> 4 files changed, 16 insertions(+), 16 deletions(-)
>
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 5/7] libnvdimm: reduce an unnecessary if branch in nd_region_activate()
2020-08-20 2:16 ` [PATCH v3 5/7] libnvdimm: reduce an unnecessary if branch in nd_region_activate() Zhen Lei
@ 2020-08-27 7:04 ` Leizhen (ThunderTown)
0 siblings, 0 replies; 12+ messages in thread
From: Leizhen (ThunderTown) @ 2020-08-27 7:04 UTC (permalink / raw)
To: Oliver O'Halloran, Dan Williams, Vishal Verma, Dave Jiang,
Ira Weiny, Markus Elfring, linux-nvdimm, linux-kernel
I will drop this patch, because I have a doubt:
Suppose the nd_region->ndr_mappings is 4, and for each nd_region->mapping[],
the value of num_flush is "0, 0, 4, 0", so the flush_data_size is "1 + 1 + 5 + 1", * sizeof(void *).
But in ndrd_get_flush_wpq() or ndrd_set_flush_wpq(), the expression is
"ndrd->flush_wpq[dimm * num + (hint & mask)]", I don't think the memory "ndrd" allocated is enough.
Please refer call chain: nd_region_activate() --> nvdimm_map_flush() --> ndrd_set_flush_wpq()
for (i = 0; i < nd_region->ndr_mappings; i++) {
struct nd_mapping *nd_mapping = &nd_region->mapping[i];
struct nvdimm *nvdimm = nd_mapping->nvdimm;
/* at least one null hint slot per-dimm for the "no-hint" case */
flush_data_size += sizeof(void *);
num_flush = min_not_zero(num_flush, nvdimm->num_flush);
if (!nvdimm->num_flush)
continue;
flush_data_size += nvdimm->num_flush * sizeof(void *);
}
ndrd = devm_kzalloc(dev, sizeof(*ndrd) + flush_data_size, GFP_KERNEL);
On 2020/8/20 10:16, Zhen Lei wrote:
> According to the original code logic:
> if (!nvdimm->num_flush) {
> flush_data_size += sizeof(void *);
> //nvdimm->num_flush is zero now, add 1) have no side effects
> } else {
> flush_data_size += sizeof(void *);
> 1) flush_data_size += nvdimm->num_flush * sizeof(void *);
> }
>
> Obviously, the above code snippet can be reduced to one statement:
> flush_data_size += (nvdimm->num_flush + 1) * sizeof(void *);
>
> No functional change.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
> drivers/nvdimm/region_devs.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
> index 7cf9c7d857909ce..49be115c9189eff 100644
> --- a/drivers/nvdimm/region_devs.c
> +++ b/drivers/nvdimm/region_devs.c
> @@ -77,11 +77,8 @@ int nd_region_activate(struct nd_region *nd_region)
> }
>
> /* at least one null hint slot per-dimm for the "no-hint" case */
> - flush_data_size += sizeof(void *);
> + flush_data_size += (nvdimm->num_flush + 1) * sizeof(void *);
> num_flush = min_not_zero(num_flush, nvdimm->num_flush);
> - if (!nvdimm->num_flush)
> - continue;
> - flush_data_size += nvdimm->num_flush * sizeof(void *);
> }
> nvdimm_bus_unlock(&nd_region->dev);
>
>
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2020-08-27 7:04 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-20 2:16 [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Zhen Lei
2020-08-20 2:16 ` [PATCH v3 1/7] libnvdimm: fix memory leaks in of_pmem.c Zhen Lei
2020-08-20 2:16 ` [PATCH v3 2/7] libnvdimm: add sanity check for provider_name in of_pmem_region_probe() Zhen Lei
2020-08-20 2:16 ` [PATCH v3 3/7] libnvdimm: simplify walk_to_nvdimm_bus() Zhen Lei
2020-08-20 2:16 ` [PATCH v3 4/7] libnvdimm: reduce an unnecessary if branch in nd_region_create() Zhen Lei
2020-08-20 2:16 ` [PATCH v3 5/7] libnvdimm: reduce an unnecessary if branch in nd_region_activate() Zhen Lei
2020-08-27 7:04 ` Leizhen (ThunderTown)
2020-08-20 2:16 ` [PATCH v3 6/7] libnvdimm: make sure EXPORT_SYMBOL_GPL(nvdimm_flush) close to its function Zhen Lei
2020-08-20 11:05 ` Pankaj Gupta
2020-08-20 2:16 ` [PATCH v3 7/7] libnvdimm: slightly simplify available_slots_show() Zhen Lei
2020-08-21 12:56 ` Salih Agenter
2020-08-27 6:35 ` [PATCH v3 0/7] bugfix and optimize for drivers/nvdimm Leizhen (ThunderTown)
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).