diff mbox

[-mm,06/13] block: Increase BIO_MAX_PAGES to PMD size if THP_SWAP enabled

Message ID 20170525064635.2832-7-ying.huang@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Huang, Ying May 25, 2017, 6:46 a.m. UTC
From: Huang Ying <ying.huang@intel.com>

In this patch, BIO_MAX_PAGES is changed from 256 to HPAGE_PMD_NR if
CONFIG_THP_SWAP is enabled and HPAGE_PMD_NR > 256.  This is to support
THP (Transparent Huge Page) swap optimization.  Where the THP will be
write to disk as a whole instead of HPAGE_PMD_NR normal pages to batch
the various operations during swap.  And the page is likely to be
written to disk to free memory when system memory goes really low, the
memory pool need to be used to avoid deadlock.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Shaohua Li <shli@fb.com>
Cc: linux-block@vger.kernel.org
---
 include/linux/bio.h | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Ming Lei May 25, 2017, 8:42 a.m. UTC | #1
On Thu, May 25, 2017 at 02:46:28PM +0800, Huang, Ying wrote:
> From: Huang Ying <ying.huang@intel.com>
> 
> In this patch, BIO_MAX_PAGES is changed from 256 to HPAGE_PMD_NR if
> CONFIG_THP_SWAP is enabled and HPAGE_PMD_NR > 256.  This is to support
> THP (Transparent Huge Page) swap optimization.  Where the THP will be
> write to disk as a whole instead of HPAGE_PMD_NR normal pages to batch
> the various operations during swap.  And the page is likely to be
> written to disk to free memory when system memory goes really low, the
> memory pool need to be used to avoid deadlock.
> 
> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Minchan Kim <minchan@kernel.org>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Ming Lei <tom.leiming@gmail.com>
> Cc: Shaohua Li <shli@fb.com>
> Cc: linux-block@vger.kernel.org
> ---
>  include/linux/bio.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index d1b04b0e99cf..314796486507 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -38,7 +38,15 @@
>  #define BIO_BUG_ON
>  #endif
>  
> +#ifdef CONFIG_THP_SWAP
> +#if HPAGE_PMD_NR > 256
> +#define BIO_MAX_PAGES		HPAGE_PMD_NR
> +#else
>  #define BIO_MAX_PAGES		256
> +#endif
> +#else
> +#define BIO_MAX_PAGES		256
> +#endif
>  
>  #define bio_prio(bio)			(bio)->bi_ioprio
>  #define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)

Last time we discussed we should use multipage bvec for this usage.

I will rebase the last post on v4.12-rc and kick if off again since
the raid cleanup is just done on v4.11.

	http://marc.info/?t=148453679000002&r=1&w=2

Thanks,
Ming
Huang, Ying May 26, 2017, 12:56 a.m. UTC | #2
Ming Lei <ming.lei@redhat.com> writes:

> On Thu, May 25, 2017 at 02:46:28PM +0800, Huang, Ying wrote:
>> From: Huang Ying <ying.huang@intel.com>
>> 
>> In this patch, BIO_MAX_PAGES is changed from 256 to HPAGE_PMD_NR if
>> CONFIG_THP_SWAP is enabled and HPAGE_PMD_NR > 256.  This is to support
>> THP (Transparent Huge Page) swap optimization.  Where the THP will be
>> write to disk as a whole instead of HPAGE_PMD_NR normal pages to batch
>> the various operations during swap.  And the page is likely to be
>> written to disk to free memory when system memory goes really low, the
>> memory pool need to be used to avoid deadlock.
>> 
>> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
>> Cc: Johannes Weiner <hannes@cmpxchg.org>
>> Cc: Minchan Kim <minchan@kernel.org>
>> Cc: Jens Axboe <axboe@kernel.dk>
>> Cc: Ming Lei <tom.leiming@gmail.com>
>> Cc: Shaohua Li <shli@fb.com>
>> Cc: linux-block@vger.kernel.org
>> ---
>>  include/linux/bio.h | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>> 
>> diff --git a/include/linux/bio.h b/include/linux/bio.h
>> index d1b04b0e99cf..314796486507 100644
>> --- a/include/linux/bio.h
>> +++ b/include/linux/bio.h
>> @@ -38,7 +38,15 @@
>>  #define BIO_BUG_ON
>>  #endif
>>  
>> +#ifdef CONFIG_THP_SWAP
>> +#if HPAGE_PMD_NR > 256
>> +#define BIO_MAX_PAGES		HPAGE_PMD_NR
>> +#else
>>  #define BIO_MAX_PAGES		256
>> +#endif
>> +#else
>> +#define BIO_MAX_PAGES		256
>> +#endif
>>  
>>  #define bio_prio(bio)			(bio)->bi_ioprio
>>  #define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)
>
> Last time we discussed we should use multipage bvec for this usage.
>
> I will rebase the last post on v4.12-rc and kick if off again since
> the raid cleanup is just done on v4.11.
>
> 	http://marc.info/?t=148453679000002&r=1&w=2

Thanks for your information!  I will rebase my patchset on that after
they are merged.  From now on, this patch and the next one [07/13] is
only a temporary workaround for testing.

Best Regards,
Huang, Ying

> Thanks,
> Ming
diff mbox

Patch

diff --git a/include/linux/bio.h b/include/linux/bio.h
index d1b04b0e99cf..314796486507 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -38,7 +38,15 @@ 
 #define BIO_BUG_ON
 #endif
 
+#ifdef CONFIG_THP_SWAP
+#if HPAGE_PMD_NR > 256
+#define BIO_MAX_PAGES		HPAGE_PMD_NR
+#else
 #define BIO_MAX_PAGES		256
+#endif
+#else
+#define BIO_MAX_PAGES		256
+#endif
 
 #define bio_prio(bio)			(bio)->bi_ioprio
 #define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)