* [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE @ 2020-10-22 13:15 vjitta 2020-11-03 23:27 ` Minchan Kim 0 siblings, 1 reply; 9+ messages in thread From: vjitta @ 2020-10-22 13:15 UTC (permalink / raw) To: glider, dan.j.williams, broonie, mhiramat Cc: linux-kernel, akpm, vjitta, Yogesh Lal, Vinayak Menon From: Yogesh Lal <ylal@codeaurora.org> Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. Aim is to have configurable value for STACK_HASH_SIZE, so depend on use case one can configure it. One example is of Page Owner, default value of STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. Making it configurable and use lower value helps to enable features like CONFIG_PAGE_OWNER without any significant overhead. Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> --- lib/Kconfig | 9 +++++++++ lib/stackdepot.c | 3 +-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/Kconfig b/lib/Kconfig index 18d76b6..b3f8259 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -651,6 +651,15 @@ config STACKDEPOT bool select STACKTRACE +config STACK_HASH_ORDER_SHIFT + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" + range 12 20 + default 20 + depends on STACKDEPOT + help + Select the hash size as a power of 2 for the stackdepot hash table. + Choose a lower value to reduce the memory impact. + config SBITMAP bool diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 2caffc6..413c20b 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -142,8 +142,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, return stack; } -#define STACK_HASH_ORDER 20 -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) #define STACK_HASH_SEED 0x9747b28c -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation 2.7.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-10-22 13:15 [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE vjitta @ 2020-11-03 23:27 ` Minchan Kim 2020-11-04 10:29 ` Vijayanand Jitta 2020-11-19 3:34 ` Zhenhua Huang 0 siblings, 2 replies; 9+ messages in thread From: Minchan Kim @ 2020-11-03 23:27 UTC (permalink / raw) To: vjitta, linux-mm Cc: glider, Dan Williams, broonie, mhiramat, linux-kernel, Andrew Morton, Yogesh Lal, Vinayak Menon Sorry if this mail corrupts the mail thread or had heavy mangling since I lost this mail from my mailbox so I am sending this mail by web gmail. On Thu, Oct 22, 2020 at 10:18 AM <vjitta@codeaurora.org> wrote: > > From: Yogesh Lal <ylal@codeaurora.org> > > Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. > > Aim is to have configurable value for STACK_HASH_SIZE, > so depend on use case one can configure it. > > One example is of Page Owner, default value of > STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. > Making it configurable and use lower value helps to enable features like > CONFIG_PAGE_OWNER without any significant overhead. > > Signed-off-by: Yogesh Lal <ylal@codeaurora.org> > Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> > Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> > --- > lib/Kconfig | 9 +++++++++ > lib/stackdepot.c | 3 +-- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/lib/Kconfig b/lib/Kconfig > index 18d76b6..b3f8259 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -651,6 +651,15 @@ config STACKDEPOT > bool > select STACKTRACE > > +config STACK_HASH_ORDER_SHIFT > + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" > + range 12 20 > + default 20 > + depends on STACKDEPOT > + help > + Select the hash size as a power of 2 for the stackdepot hash table. > + Choose a lower value to reduce the memory impact. > + > config SBITMAP > bool > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > index 2caffc6..413c20b 100644 > --- a/lib/stackdepot.c > +++ b/lib/stackdepot.c > @@ -142,8 +142,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, > return stack; > } > > -#define STACK_HASH_ORDER 20 > -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) > +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) > #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) > #define STACK_HASH_SEED 0x9747b28c > > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation > 2.7.4 > 1. When we don't use page_owner, we don't want to waste any memory for stackdepot hash array. 2. When we use page_owner, we want to have reasonable stackdeport hash array With this configuration, it couldn't meet since we always need to reserve a reasonable size for the array. Can't we make the hash size as a kernel parameter? With it, we could use it like this. 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory when we don't use page_owner 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size when we use page_owner. -- Kind regards, Minchan Kim ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-03 23:27 ` Minchan Kim @ 2020-11-04 10:29 ` Vijayanand Jitta 2020-11-12 12:56 ` Vijayanand Jitta 2020-11-19 3:34 ` Zhenhua Huang 1 sibling, 1 reply; 9+ messages in thread From: Vijayanand Jitta @ 2020-11-04 10:29 UTC (permalink / raw) To: Minchan Kim, linux-mm Cc: glider, Dan Williams, broonie, mhiramat, linux-kernel, Andrew Morton, Yogesh Lal, Vinayak Menon On 11/4/2020 4:57 AM, Minchan Kim wrote: > Sorry if this mail corrupts the mail thread or had heavy mangling > since I lost this mail from my mailbox so I am sending this mail by > web gmail. > > On Thu, Oct 22, 2020 at 10:18 AM <vjitta@codeaurora.org> wrote: >> >> From: Yogesh Lal <ylal@codeaurora.org> >> >> Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. >> >> Aim is to have configurable value for STACK_HASH_SIZE, >> so depend on use case one can configure it. >> >> One example is of Page Owner, default value of >> STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. >> Making it configurable and use lower value helps to enable features like >> CONFIG_PAGE_OWNER without any significant overhead. >> >> Signed-off-by: Yogesh Lal <ylal@codeaurora.org> >> Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> >> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> >> --- >> lib/Kconfig | 9 +++++++++ >> lib/stackdepot.c | 3 +-- >> 2 files changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/lib/Kconfig b/lib/Kconfig >> index 18d76b6..b3f8259 100644 >> --- a/lib/Kconfig >> +++ b/lib/Kconfig >> @@ -651,6 +651,15 @@ config STACKDEPOT >> bool >> select STACKTRACE >> >> +config STACK_HASH_ORDER_SHIFT >> + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" >> + range 12 20 >> + default 20 >> + depends on STACKDEPOT >> + help >> + Select the hash size as a power of 2 for the stackdepot hash table. >> + Choose a lower value to reduce the memory impact. >> + >> config SBITMAP >> bool >> >> diff --git a/lib/stackdepot.c b/lib/stackdepot.c >> index 2caffc6..413c20b 100644 >> --- a/lib/stackdepot.c >> +++ b/lib/stackdepot.c >> @@ -142,8 +142,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, >> return stack; >> } >> >> -#define STACK_HASH_ORDER 20 >> -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) >> +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) >> #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) >> #define STACK_HASH_SEED 0x9747b28c >> >> -- >> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation >> 2.7.4 >> > > 1. When we don't use page_owner, we don't want to waste any memory for > stackdepot hash array. > 2. When we use page_owner, we want to have reasonable stackdeport hash array > > With this configuration, it couldn't meet since we always need to > reserve a reasonable size for the array. > Can't we make the hash size as a kernel parameter? > With it, we could use it like this. > > 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory > when we don't use page_owner > 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size > when we use page_owner. > > This idea looks fine to me. Andrew and others would like to hear your comments as well on this before implementing. Thanks, Vijay -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-04 10:29 ` Vijayanand Jitta @ 2020-11-12 12:56 ` Vijayanand Jitta 2020-11-12 22:56 ` Andrew Morton 0 siblings, 1 reply; 9+ messages in thread From: Vijayanand Jitta @ 2020-11-12 12:56 UTC (permalink / raw) To: Minchan Kim, linux-mm Cc: glider, Dan Williams, broonie, mhiramat, linux-kernel, Andrew Morton, Yogesh Lal, Vinayak Menon On 11/4/2020 3:59 PM, Vijayanand Jitta wrote: > > > On 11/4/2020 4:57 AM, Minchan Kim wrote: >> Sorry if this mail corrupts the mail thread or had heavy mangling >> since I lost this mail from my mailbox so I am sending this mail by >> web gmail. >> >> On Thu, Oct 22, 2020 at 10:18 AM <vjitta@codeaurora.org> wrote: >>> >>> From: Yogesh Lal <ylal@codeaurora.org> >>> >>> Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. >>> >>> Aim is to have configurable value for STACK_HASH_SIZE, >>> so depend on use case one can configure it. >>> >>> One example is of Page Owner, default value of >>> STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. >>> Making it configurable and use lower value helps to enable features like >>> CONFIG_PAGE_OWNER without any significant overhead. >>> >>> Signed-off-by: Yogesh Lal <ylal@codeaurora.org> >>> Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> >>> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> >>> --- >>> lib/Kconfig | 9 +++++++++ >>> lib/stackdepot.c | 3 +-- >>> 2 files changed, 10 insertions(+), 2 deletions(-) >>> >>> diff --git a/lib/Kconfig b/lib/Kconfig >>> index 18d76b6..b3f8259 100644 >>> --- a/lib/Kconfig >>> +++ b/lib/Kconfig >>> @@ -651,6 +651,15 @@ config STACKDEPOT >>> bool >>> select STACKTRACE >>> >>> +config STACK_HASH_ORDER_SHIFT >>> + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" >>> + range 12 20 >>> + default 20 >>> + depends on STACKDEPOT >>> + help >>> + Select the hash size as a power of 2 for the stackdepot hash table. >>> + Choose a lower value to reduce the memory impact. >>> + >>> config SBITMAP >>> bool >>> >>> diff --git a/lib/stackdepot.c b/lib/stackdepot.c >>> index 2caffc6..413c20b 100644 >>> --- a/lib/stackdepot.c >>> +++ b/lib/stackdepot.c >>> @@ -142,8 +142,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, >>> return stack; >>> } >>> >>> -#define STACK_HASH_ORDER 20 >>> -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) >>> +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) >>> #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) >>> #define STACK_HASH_SEED 0x9747b28c >>> >>> -- >>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation >>> 2.7.4 >>> >> >> 1. When we don't use page_owner, we don't want to waste any memory for >> stackdepot hash array. >> 2. When we use page_owner, we want to have reasonable stackdeport hash array >> >> With this configuration, it couldn't meet since we always need to >> reserve a reasonable size for the array. >> Can't we make the hash size as a kernel parameter? >> With it, we could use it like this. >> >> 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory >> when we don't use page_owner >> 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size >> when we use page_owner. >> >> > > This idea looks fine to me. Andrew and others would like to hear your > comments as well on this before implementing. > > Thanks, > Vijay > Awaiting for comments from Andrew and others. Thanks, Vijay -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-12 12:56 ` Vijayanand Jitta @ 2020-11-12 22:56 ` Andrew Morton 2020-11-17 20:42 ` Minchan Kim 0 siblings, 1 reply; 9+ messages in thread From: Andrew Morton @ 2020-11-12 22:56 UTC (permalink / raw) To: Vijayanand Jitta Cc: Minchan Kim, linux-mm, glider, Dan Williams, broonie, mhiramat, linux-kernel, Yogesh Lal, Vinayak Menon On Thu, 12 Nov 2020 18:26:24 +0530 Vijayanand Jitta <vjitta@codeaurora.org> wrote: > >> 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory > >> when we don't use page_owner > >> 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size > >> when we use page_owner. > >> > >> > > > > This idea looks fine to me. Andrew and others would like to hear your > > comments as well on this before implementing. > > > > Thanks, > > Vijay > > > > Awaiting for comments from Andrew and others. I don't actually understand the problem. What is it about page-owner that causes stackdepot to consume additional memory? As far as I can tell, sizeof(struct stack_record) isn't affected by page-owner? ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-12 22:56 ` Andrew Morton @ 2020-11-17 20:42 ` Minchan Kim 0 siblings, 0 replies; 9+ messages in thread From: Minchan Kim @ 2020-11-17 20:42 UTC (permalink / raw) To: Andrew Morton Cc: Vijayanand Jitta, linux-mm, glider, Dan Williams, broonie, mhiramat, linux-kernel, Yogesh Lal, Vinayak Menon On Thu, Nov 12, 2020 at 02:56:49PM -0800, Andrew Morton wrote: > On Thu, 12 Nov 2020 18:26:24 +0530 Vijayanand Jitta <vjitta@codeaurora.org> wrote: > > > >> 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory > > >> when we don't use page_owner > > >> 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size > > >> when we use page_owner. > > >> > > >> > > > > > > This idea looks fine to me. Andrew and others would like to hear your > > > comments as well on this before implementing. > > > > > > Thanks, > > > Vijay > > > > > > > Awaiting for comments from Andrew and others. > > I don't actually understand the problem. > > What is it about page-owner that causes stackdepot to consume > additional memory? As far as I can tell, sizeof(struct stack_record) > isn't affected by page-owner? > Thing is once we build stackdepot due to the dependency from page_owner, it will consume 8M regardless of using page_owner. #define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) static struct stack_record *stack_table[STACK_HASH_SIZE] = { [0 ... STACK_HASH_SIZE - 1] = NULL }; So if we decide the size option at build time, we should consume the memory anyway regardless of page_owner enabling in runtime. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-03 23:27 ` Minchan Kim 2020-11-04 10:29 ` Vijayanand Jitta @ 2020-11-19 3:34 ` Zhenhua Huang 2020-11-20 5:04 ` Minchan Kim 1 sibling, 1 reply; 9+ messages in thread From: Zhenhua Huang @ 2020-11-19 3:34 UTC (permalink / raw) To: Minchan Kim Cc: vjitta, linux-mm, glider, Dan Williams, broonie, mhiramat, linux-kernel, Andrew Morton, Yogesh Lal, Vinayak Menon, tingwei On Wed, Nov 04, 2020 at 07:27:03AM +0800, Minchan Kim wrote: > Sorry if this mail corrupts the mail thread or had heavy mangling > since I lost this mail from my mailbox so I am sending this mail by > web gmail. > > On Thu, Oct 22, 2020 at 10:18 AM <vjitta@codeaurora.org> wrote: > > > > From: Yogesh Lal <ylal@codeaurora.org> > > > > Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. > > > > Aim is to have configurable value for STACK_HASH_SIZE, > > so depend on use case one can configure it. > > > > One example is of Page Owner, default value of > > STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. > > Making it configurable and use lower value helps to enable features like > > CONFIG_PAGE_OWNER without any significant overhead. > > > > Signed-off-by: Yogesh Lal <ylal@codeaurora.org> > > Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> > > Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> > > --- > > lib/Kconfig | 9 +++++++++ > > lib/stackdepot.c | 3 +-- > > 2 files changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/lib/Kconfig b/lib/Kconfig > > index 18d76b6..b3f8259 100644 > > --- a/lib/Kconfig > > +++ b/lib/Kconfig > > @@ -651,6 +651,15 @@ config STACKDEPOT > > bool > > select STACKTRACE > > > > +config STACK_HASH_ORDER_SHIFT > > + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" > > + range 12 20 > > + default 20 > > + depends on STACKDEPOT > > + help > > + Select the hash size as a power of 2 for the stackdepot hash > > table. > > + Choose a lower value to reduce the memory impact. > > + > > config SBITMAP > > bool > > > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > > index 2caffc6..413c20b 100644 > > --- a/lib/stackdepot.c > > +++ b/lib/stackdepot.c > > @@ -142,8 +142,7 @@ static struct stack_record *depot_alloc_stack(unsigned > > long *entries, int size, > > return stack; > > } > > > > -#define STACK_HASH_ORDER 20 > > -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) > > +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) > > #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) > > #define STACK_HASH_SEED 0x9747b28c > > > > -- > > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > > of Code Aurora Forum, hosted by The Linux Foundation > > 2.7.4 > > > > 1. When we don't use page_owner, we don't want to waste any memory for > stackdepot hash array. > 2. When we use page_owner, we want to have reasonable stackdeport hash array > > With this configuration, it couldn't meet since we always need to > reserve a reasonable size for the array. > Can't we make the hash size as a kernel parameter? > With it, we could use it like this. > > 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory > when we don't use page_owner > 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size > when we use page_owner. Seems we have other users like kasan, and dma_buf_ref which we introduced. Also we can't guarantee there will not be any other users for stackdepot, so it's better we not depend on only page owner? > > > -- > Kind regards, > Minchan Kim > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-19 3:34 ` Zhenhua Huang @ 2020-11-20 5:04 ` Minchan Kim 2020-11-20 7:08 ` Zhenhua Huang 0 siblings, 1 reply; 9+ messages in thread From: Minchan Kim @ 2020-11-20 5:04 UTC (permalink / raw) To: Zhenhua Huang Cc: vjitta, linux-mm, glider, Dan Williams, broonie, mhiramat, linux-kernel, Andrew Morton, Yogesh Lal, Vinayak Menon, tingwei On Thu, Nov 19, 2020 at 11:34:32AM +0800, Zhenhua Huang wrote: > On Wed, Nov 04, 2020 at 07:27:03AM +0800, Minchan Kim wrote: > > Sorry if this mail corrupts the mail thread or had heavy mangling > > since I lost this mail from my mailbox so I am sending this mail by > > web gmail. > > > > On Thu, Oct 22, 2020 at 10:18 AM <vjitta@codeaurora.org> wrote: > > > > > > From: Yogesh Lal <ylal@codeaurora.org> > > > > > > Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. > > > > > > Aim is to have configurable value for STACK_HASH_SIZE, > > > so depend on use case one can configure it. > > > > > > One example is of Page Owner, default value of > > > STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. > > > Making it configurable and use lower value helps to enable features like > > > CONFIG_PAGE_OWNER without any significant overhead. > > > > > > Signed-off-by: Yogesh Lal <ylal@codeaurora.org> > > > Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> > > > Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> > > > --- > > > lib/Kconfig | 9 +++++++++ > > > lib/stackdepot.c | 3 +-- > > > 2 files changed, 10 insertions(+), 2 deletions(-) > > > > > > diff --git a/lib/Kconfig b/lib/Kconfig > > > index 18d76b6..b3f8259 100644 > > > --- a/lib/Kconfig > > > +++ b/lib/Kconfig > > > @@ -651,6 +651,15 @@ config STACKDEPOT > > > bool > > > select STACKTRACE > > > > > > +config STACK_HASH_ORDER_SHIFT > > > + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" > > > + range 12 20 > > > + default 20 > > > + depends on STACKDEPOT > > > + help > > > + Select the hash size as a power of 2 for the stackdepot hash > > > table. > > > + Choose a lower value to reduce the memory impact. > > > + > > > config SBITMAP > > > bool > > > > > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > > > index 2caffc6..413c20b 100644 > > > --- a/lib/stackdepot.c > > > +++ b/lib/stackdepot.c > > > @@ -142,8 +142,7 @@ static struct stack_record *depot_alloc_stack(unsigned > > > long *entries, int size, > > > return stack; > > > } > > > > > > -#define STACK_HASH_ORDER 20 > > > -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) > > > +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) > > > #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) > > > #define STACK_HASH_SEED 0x9747b28c > > > > > > -- > > > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > > > of Code Aurora Forum, hosted by The Linux Foundation > > > 2.7.4 > > > > > > > 1. When we don't use page_owner, we don't want to waste any memory for > > stackdepot hash array. > > 2. When we use page_owner, we want to have reasonable stackdeport hash array > > > > With this configuration, it couldn't meet since we always need to > > reserve a reasonable size for the array. > > Can't we make the hash size as a kernel parameter? > > With it, we could use it like this. > > > > 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory > > when we don't use page_owner > > 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size > > when we use page_owner. > Seems we have other users like kasan, and dma_buf_ref which we introduced. > Also we can't guarantee there will not be any other users for stackdepot, so > it's better we not depend on only page owner? I didn't mean to make it page_owner dependent. What I suggested is just to define kernel parameter for stackdeport hash size so admin could override it at right size when we really need it. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE 2020-11-20 5:04 ` Minchan Kim @ 2020-11-20 7:08 ` Zhenhua Huang 0 siblings, 0 replies; 9+ messages in thread From: Zhenhua Huang @ 2020-11-20 7:08 UTC (permalink / raw) To: Minchan Kim Cc: vjitta, linux-mm, glider, Dan Williams, broonie, mhiramat, linux-kernel, Andrew Morton, Yogesh Lal, Vinayak Menon, tingwei On Fri, Nov 20, 2020 at 01:04:23PM +0800, Minchan Kim wrote: > On Thu, Nov 19, 2020 at 11:34:32AM +0800, Zhenhua Huang wrote: > > On Wed, Nov 04, 2020 at 07:27:03AM +0800, Minchan Kim wrote: > > > Sorry if this mail corrupts the mail thread or had heavy mangling > > > since I lost this mail from my mailbox so I am sending this mail by > > > web gmail. > > > > > > On Thu, Oct 22, 2020 at 10:18 AM <vjitta@codeaurora.org> wrote: > > > > > > > > From: Yogesh Lal <ylal@codeaurora.org> > > > > > > > > Use STACK_HASH_ORDER_SHIFT to configure STACK_HASH_SIZE. > > > > > > > > Aim is to have configurable value for STACK_HASH_SIZE, > > > > so depend on use case one can configure it. > > > > > > > > One example is of Page Owner, default value of > > > > STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. > > > > Making it configurable and use lower value helps to enable features > like > > > > CONFIG_PAGE_OWNER without any significant overhead. > > > > > > > > Signed-off-by: Yogesh Lal <ylal@codeaurora.org> > > > > Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> > > > > Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> > > > > --- > > > > lib/Kconfig | 9 +++++++++ > > > > lib/stackdepot.c | 3 +-- > > > > 2 files changed, 10 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/lib/Kconfig b/lib/Kconfig > > > > index 18d76b6..b3f8259 100644 > > > > --- a/lib/Kconfig > > > > +++ b/lib/Kconfig > > > > @@ -651,6 +651,15 @@ config STACKDEPOT > > > > bool > > > > select STACKTRACE > > > > > > > > +config STACK_HASH_ORDER_SHIFT > > > > + int "stack depot hash size (12 => 4KB, 20 => 1024KB)" > > > > + range 12 20 > > > > + default 20 > > > > + depends on STACKDEPOT > > > > + help > > > > + Select the hash size as a power of 2 for the stackdepot > hash > > > > table. > > > > + Choose a lower value to reduce the memory impact. > > > > + > > > > config SBITMAP > > > > bool > > > > > > > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > > > > index 2caffc6..413c20b 100644 > > > > --- a/lib/stackdepot.c > > > > +++ b/lib/stackdepot.c > > > > @@ -142,8 +142,7 @@ static struct stack_record > *depot_alloc_stack(unsigned > > > > long *entries, int size, > > > > return stack; > > > > } > > > > > > > > -#define STACK_HASH_ORDER 20 > > > > -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) > > > > +#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER_SHIFT) > > > > #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) > > > > #define STACK_HASH_SEED 0x9747b28c > > > > > > > > -- > > > > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a > member > > > > of Code Aurora Forum, hosted by The Linux Foundation > > > > 2.7.4 > > > > > > > > > > 1. When we don't use page_owner, we don't want to waste any memory for > > > stackdepot hash array. > > > 2. When we use page_owner, we want to have reasonable stackdeport hash > array > > > > > > With this configuration, it couldn't meet since we always need to > > > reserve a reasonable size for the array. > > > Can't we make the hash size as a kernel parameter? > > > With it, we could use it like this. > > > > > > 1. page_owner=off, stackdepot_stack_hash=0 -> no more wasted memory > > > when we don't use page_owner > > > 2. page_owner=on, stackdepot_stack_hash=8M -> reasonable hash size > > > when we use page_owner. > > Seems we have other users like kasan, and dma_buf_ref which we > introduced. > > Also we can't guarantee there will not be any other users for > stackdepot, so > > it's better we not depend on only page owner? > > I didn't mean to make it page_owner dependent. What I suggested is just > to define kernel parameter for stackdeport hash size so admin could > override it at right size when we really need it. OK, Thanks Minchan for explanation. It's a good idea then, admin needs to consider all users but, especailly when setting it to 0... Thanks, Zhenhua ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-11-20 7:08 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-10-22 13:15 [PATCH] lib: stackdepot: Add support to configure STACK_HASH_SIZE vjitta 2020-11-03 23:27 ` Minchan Kim 2020-11-04 10:29 ` Vijayanand Jitta 2020-11-12 12:56 ` Vijayanand Jitta 2020-11-12 22:56 ` Andrew Morton 2020-11-17 20:42 ` Minchan Kim 2020-11-19 3:34 ` Zhenhua Huang 2020-11-20 5:04 ` Minchan Kim 2020-11-20 7:08 ` Zhenhua Huang
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