| Message ID | 20240402001739.2521623-2-horenchuang@bytedance.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Improved Memory Tier Creation for CPUless NUMA Nodes | expand |
On Tue, 2 Apr 2024 00:17:37 +0000 "Ho-Ren (Jack) Chuang" <horenchuang@bytedance.com> wrote: > Since different memory devices require finding, allocating, and putting > memory types, these common steps are abstracted in this patch, > enhancing the scalability and conciseness of the code. > > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> > Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Hi, I know this is a late entry to the discussion but a few comments inline. (sorry I didn't look earlier!) All opportunities to improve code complexity and readability as a result of your factoring out. Jonathan > --- > drivers/dax/kmem.c | 20 ++------------------ > include/linux/memory-tiers.h | 13 +++++++++++++ > mm/memory-tiers.c | 32 ++++++++++++++++++++++++++++++++ > 3 files changed, 47 insertions(+), 18 deletions(-) > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > index 42ee360cf4e3..01399e5b53b2 100644 > --- a/drivers/dax/kmem.c > +++ b/drivers/dax/kmem.c > @@ -55,21 +55,10 @@ static LIST_HEAD(kmem_memory_types); > > static struct memory_dev_type *kmem_find_alloc_memory_type(int adist) > { > - bool found = false; > struct memory_dev_type *mtype; > > mutex_lock(&kmem_memory_type_lock); could use guard(mutex)(&kmem_memory_type_lock); return mt_find_alloc_memory_type(adist, &kmem_memory_types); I'm fine if you ignore this comment though as may be other functions in here that could take advantage of the cleanup.h stuff in a future patch. > - list_for_each_entry(mtype, &kmem_memory_types, list) { > - if (mtype->adistance == adist) { > - found = true; > - break; > - } > - } > - if (!found) { > - mtype = alloc_memory_type(adist); > - if (!IS_ERR(mtype)) > - list_add(&mtype->list, &kmem_memory_types); > - } > + mtype = mt_find_alloc_memory_type(adist, &kmem_memory_types); > mutex_unlock(&kmem_memory_type_lock); > > return mtype; > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h > index 69e781900082..a44c03c2ba3a 100644 > --- a/include/linux/memory-tiers.h > +++ b/include/linux/memory-tiers.h > @@ -48,6 +48,9 @@ int mt_calc_adistance(int node, int *adist); > int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, > const char *source); > int mt_perf_to_adistance(struct access_coordinate *perf, int *adist); > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, > + struct list_head *memory_types); That indent looks unusual. Align the start of struct with start of int. > +void mt_put_memory_types(struct list_head *memory_types); > #ifdef CONFIG_MIGRATION > int next_demotion_node(int node); > void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets); > @@ -136,5 +139,15 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis > { > return -EIO; > } > + > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) > +{ > + return NULL; > +} > + > +void mt_put_memory_types(struct list_head *memory_types) > +{ > + No blank line needed here. > +} > #endif /* CONFIG_NUMA */ > #endif /* _LINUX_MEMORY_TIERS_H */ > diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c > index 0537664620e5..974af10cfdd8 100644 > --- a/mm/memory-tiers.c > +++ b/mm/memory-tiers.c > @@ -623,6 +623,38 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype) > } > EXPORT_SYMBOL_GPL(clear_node_memory_type); > > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) Breaking this out as a separate function provides opportunity to improve it. Maybe a follow up patch makes sense given it would no longer be a straight forward code move. However in my view it would be simple enough to be obvious even within this patch. > +{ > + bool found = false; > + struct memory_dev_type *mtype; > + > + list_for_each_entry(mtype, memory_types, list) { > + if (mtype->adistance == adist) { > + found = true; Why not return here? return mtype; > + break; > + } > + } > + if (!found) { If returning above, no need for found variable - just do this unconditionally. + I suggest you flip logic for simpler to follow code flow. It's more code but I think a bit easier to read as error handling is out of the main simple flow. mtype = alloc_memory_type(adist); if (IS_ERR(mtype)) return mtype; list_add(&mtype->list, memory_types); return mtype; > + mtype = alloc_memory_type(adist); > + if (!IS_ERR(mtype)) > + list_add(&mtype->list, memory_types); > + } > + > + return mtype; > +} > +EXPORT_SYMBOL_GPL(mt_find_alloc_memory_type); > + > +void mt_put_memory_types(struct list_head *memory_types) > +{ > + struct memory_dev_type *mtype, *mtn; > + > + list_for_each_entry_safe(mtype, mtn, memory_types, list) { > + list_del(&mtype->list); > + put_memory_type(mtype); > + } > +} > +EXPORT_SYMBOL_GPL(mt_put_memory_types); > + > static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) > { > pr_info(
Hi Jonathan, Thanks for your feedback. I will fix them (inlined) in the next V11. No worries, it's never too late! On Wed, Apr 3, 2024 at 9:52 AM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > On Tue, 2 Apr 2024 00:17:37 +0000 > "Ho-Ren (Jack) Chuang" <horenchuang@bytedance.com> wrote: > > > Since different memory devices require finding, allocating, and putting > > memory types, these common steps are abstracted in this patch, > > enhancing the scalability and conciseness of the code. > > > > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> > > Reviewed-by: "Huang, Ying" <ying.huang@intel.com> > > Hi, > > I know this is a late entry to the discussion but a few comments inline. > (sorry I didn't look earlier!) > > All opportunities to improve code complexity and readability as a result > of your factoring out. > > Jonathan > > > > --- > > drivers/dax/kmem.c | 20 ++------------------ > > include/linux/memory-tiers.h | 13 +++++++++++++ > > mm/memory-tiers.c | 32 ++++++++++++++++++++++++++++++++ > > 3 files changed, 47 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > > index 42ee360cf4e3..01399e5b53b2 100644 > > --- a/drivers/dax/kmem.c > > +++ b/drivers/dax/kmem.c > > @@ -55,21 +55,10 @@ static LIST_HEAD(kmem_memory_types); > > > > static struct memory_dev_type *kmem_find_alloc_memory_type(int adist) > > { > > - bool found = false; > > struct memory_dev_type *mtype; > > > > mutex_lock(&kmem_memory_type_lock); > could use > > guard(mutex)(&kmem_memory_type_lock); > return mt_find_alloc_memory_type(adist, &kmem_memory_types); > I will change it accordingly. > I'm fine if you ignore this comment though as may be other functions in > here that could take advantage of the cleanup.h stuff in a future patch. > > > - list_for_each_entry(mtype, &kmem_memory_types, list) { > > - if (mtype->adistance == adist) { > > - found = true; > > - break; > > - } > > - } > > - if (!found) { > > - mtype = alloc_memory_type(adist); > > - if (!IS_ERR(mtype)) > > - list_add(&mtype->list, &kmem_memory_types); > > - } > > + mtype = mt_find_alloc_memory_type(adist, &kmem_memory_types); > > mutex_unlock(&kmem_memory_type_lock); > > > > return mtype; > > > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h > > index 69e781900082..a44c03c2ba3a 100644 > > --- a/include/linux/memory-tiers.h > > +++ b/include/linux/memory-tiers.h > > @@ -48,6 +48,9 @@ int mt_calc_adistance(int node, int *adist); > > int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, > > const char *source); > > int mt_perf_to_adistance(struct access_coordinate *perf, int *adist); > > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, > > + struct list_head *memory_types); > > That indent looks unusual. Align the start of struct with start of int. > I can make this aligned but it will show another warning: "WARNING: line length of 131 exceeds 100 columns" Is this ok? > > +void mt_put_memory_types(struct list_head *memory_types); > > #ifdef CONFIG_MIGRATION > > int next_demotion_node(int node); > > void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets); > > @@ -136,5 +139,15 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis > > { > > return -EIO; > > } > > + > > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) > > +{ > > + return NULL; > > +} > > + > > +void mt_put_memory_types(struct list_head *memory_types) > > +{ > > + > No blank line needed here. Will fix. > > +} > > #endif /* CONFIG_NUMA */ > > #endif /* _LINUX_MEMORY_TIERS_H */ > > diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c > > index 0537664620e5..974af10cfdd8 100644 > > --- a/mm/memory-tiers.c > > +++ b/mm/memory-tiers.c > > @@ -623,6 +623,38 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype) > > } > > EXPORT_SYMBOL_GPL(clear_node_memory_type); > > > > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) > > Breaking this out as a separate function provides opportunity to improve it. > Maybe a follow up patch makes sense given it would no longer be a straight > forward code move. However in my view it would be simple enough to be obvious > even within this patch. > I will just keep this as is for now to minimize the changes aka mistakes. > > +{ > > + bool found = false; > > + struct memory_dev_type *mtype; > > + > > + list_for_each_entry(mtype, memory_types, list) { > > + if (mtype->adistance == adist) { > > + found = true; > > Why not return here? > return mtype; > Yes, I can return here. I will do that and take care of the ptr returning at this point. > > + break; > > + } > > + } > > + if (!found) { > > If returning above, no need for found variable - just do this unconditionally. > + I suggest you flip logic for simpler to follow code flow. > It's more code but I think a bit easier to read as error handling is > out of the main simple flow. > > mtype = alloc_memory_type(adist); > if (IS_ERR(mtype)) > return mtype; > > list_add(&mtype->list, memory_types); > > return mtype; > Good idea! I will change it accordingly. > > + mtype = alloc_memory_type(adist); > > + if (!IS_ERR(mtype)) > > + list_add(&mtype->list, memory_types); > > + } > > + > > + return mtype; > > +} > > +EXPORT_SYMBOL_GPL(mt_find_alloc_memory_type); > > + > > +void mt_put_memory_types(struct list_head *memory_types) > > +{ > > + struct memory_dev_type *mtype, *mtn; > > + > > + list_for_each_entry_safe(mtype, mtn, memory_types, list) { > > + list_del(&mtype->list); > > + put_memory_type(mtype); > > + } > > +} > > +EXPORT_SYMBOL_GPL(mt_put_memory_types); > > + > > static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) > > { > > pr_info( >
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 42ee360cf4e3..01399e5b53b2 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -55,21 +55,10 @@ static LIST_HEAD(kmem_memory_types); static struct memory_dev_type *kmem_find_alloc_memory_type(int adist) { - bool found = false; struct memory_dev_type *mtype; mutex_lock(&kmem_memory_type_lock); - list_for_each_entry(mtype, &kmem_memory_types, list) { - if (mtype->adistance == adist) { - found = true; - break; - } - } - if (!found) { - mtype = alloc_memory_type(adist); - if (!IS_ERR(mtype)) - list_add(&mtype->list, &kmem_memory_types); - } + mtype = mt_find_alloc_memory_type(adist, &kmem_memory_types); mutex_unlock(&kmem_memory_type_lock); return mtype; @@ -77,13 +66,8 @@ static struct memory_dev_type *kmem_find_alloc_memory_type(int adist) static void kmem_put_memory_types(void) { - struct memory_dev_type *mtype, *mtn; - mutex_lock(&kmem_memory_type_lock); - list_for_each_entry_safe(mtype, mtn, &kmem_memory_types, list) { - list_del(&mtype->list); - put_memory_type(mtype); - } + mt_put_memory_types(&kmem_memory_types); mutex_unlock(&kmem_memory_type_lock); } diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h index 69e781900082..a44c03c2ba3a 100644 --- a/include/linux/memory-tiers.h +++ b/include/linux/memory-tiers.h @@ -48,6 +48,9 @@ int mt_calc_adistance(int node, int *adist); int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, const char *source); int mt_perf_to_adistance(struct access_coordinate *perf, int *adist); +struct memory_dev_type *mt_find_alloc_memory_type(int adist, + struct list_head *memory_types); +void mt_put_memory_types(struct list_head *memory_types); #ifdef CONFIG_MIGRATION int next_demotion_node(int node); void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets); @@ -136,5 +139,15 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis { return -EIO; } + +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) +{ + return NULL; +} + +void mt_put_memory_types(struct list_head *memory_types) +{ + +} #endif /* CONFIG_NUMA */ #endif /* _LINUX_MEMORY_TIERS_H */ diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c index 0537664620e5..974af10cfdd8 100644 --- a/mm/memory-tiers.c +++ b/mm/memory-tiers.c @@ -623,6 +623,38 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype) } EXPORT_SYMBOL_GPL(clear_node_memory_type); +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) +{ + bool found = false; + struct memory_dev_type *mtype; + + list_for_each_entry(mtype, memory_types, list) { + if (mtype->adistance == adist) { + found = true; + break; + } + } + if (!found) { + mtype = alloc_memory_type(adist); + if (!IS_ERR(mtype)) + list_add(&mtype->list, memory_types); + } + + return mtype; +} +EXPORT_SYMBOL_GPL(mt_find_alloc_memory_type); + +void mt_put_memory_types(struct list_head *memory_types) +{ + struct memory_dev_type *mtype, *mtn; + + list_for_each_entry_safe(mtype, mtn, memory_types, list) { + list_del(&mtype->list); + put_memory_type(mtype); + } +} +EXPORT_SYMBOL_GPL(mt_put_memory_types); + static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) { pr_info(