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* [PATCH] f2fs: fix to name f2fs GC task as per partition instead of per device
@ 2013-02-05 14:24 Namjae Jeon
  2013-02-06  4:41 ` Jaegeuk Kim
  0 siblings, 1 reply; 4+ messages in thread
From: Namjae Jeon @ 2013-02-05 14:24 UTC (permalink / raw)
  To: jaegeuk.kim
  Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel, Namjae Jeon,
	Namjae Jeon, Amit Sahrawat

From: Namjae Jeon <namjae.jeon@samsung.com>

After the commit 2184ad190a79ae2b40b5f5db1fbde5c22db6d310, it allowed
for naming GC threads based on the device.
i.e., if we have F2FS formatted partition in different devices - we will
have their GC thread names after the device. But, when we have a case like
2 or more partitions on the same device having F2FS filesystem.
In that case we are not able to differentiate between the GC threads.
So, to differentiate at all possible levels we can use the major/minor of
the device to have unique identification in the name.

Before patch:
root  9726  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:48]
root  9736  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:16]
root  9892  0.0  0.0  0  0 ?  S  14:33   0:00 [f2fs_gc-8:32]
root  9907  0.0  0.0  0  0 ?  S  14:34   0:00 [f2fs_gc-8:32]

After Patch:
root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:18]
root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:19]
root  16806  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:34]
root  16817  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:52]

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
---
 fs/f2fs/gc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 742135a..b0c1f8c 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -91,6 +91,7 @@ static int gc_thread_func(void *data)
 int start_gc_thread(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_gc_kthread *gc_th;
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
 
 	if (!test_opt(sbi, BG_GC))
 		return 0;
@@ -101,7 +102,7 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
 	sbi->gc_thread = gc_th;
 	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
-				"f2fs_gc-%s", dev_name(sbi->sb->s_bdi->dev));
+				"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 	if (IS_ERR(gc_th->f2fs_gc_task)) {
 		kfree(gc_th);
 		sbi->gc_thread = NULL;
-- 
1.7.9.5


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] f2fs: fix to name f2fs GC task as per partition instead of per device
  2013-02-05 14:24 [PATCH] f2fs: fix to name f2fs GC task as per partition instead of per device Namjae Jeon
@ 2013-02-06  4:41 ` Jaegeuk Kim
  2013-02-06  4:59   ` Namjae Jeon
  0 siblings, 1 reply; 4+ messages in thread
From: Jaegeuk Kim @ 2013-02-06  4:41 UTC (permalink / raw)
  To: Namjae Jeon
  Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel, Namjae Jeon,
	Amit Sahrawat

[-- Attachment #1: Type: text/plain, Size: 2570 bytes --]

Hi,

How about this?

2013-02-05 (화), 23:24 +0900, Namjae Jeon:
> From: Namjae Jeon <namjae.jeon@samsung.com>
> 
> After the commit 2184ad190a79ae2b40b5f5db1fbde5c22db6d310, it allowed
> for naming GC threads based on the device.
> i.e., if we have F2FS formatted partition in different devices - we will
> have their GC thread names after the device. But, when we have a case like
> 2 or more partitions on the same device having F2FS filesystem.
> In that case we are not able to differentiate between the GC threads.
> So, to differentiate at all possible levels we can use the major/minor of
> the device to have unique identification in the name.
> 
> Before patch:
> root  9726  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:48]
> root  9736  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:16]
> root  9892  0.0  0.0  0  0 ?  S  14:33   0:00 [f2fs_gc-8:32]
> root  9907  0.0  0.0  0  0 ?  S  14:34   0:00 [f2fs_gc-8:32]
> 
> After Patch:
> root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:18]
> root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:19]
> root  16806  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:34]
> root  16817  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:52]
> 

root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-sdb1]
root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-sdb2]

IMO, it would be better to describe like this.
We can simply use bdevname(bdev, name), so if no objection, I'll rebase
this patch with this.
Please, give me your opinion.
Thanks,


> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
> ---
>  fs/f2fs/gc.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 742135a..b0c1f8c 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -91,6 +91,7 @@ static int gc_thread_func(void *data)
>  int start_gc_thread(struct f2fs_sb_info *sbi)
>  {
>  	struct f2fs_gc_kthread *gc_th;
> +	dev_t dev = sbi->sb->s_bdev->bd_dev;
>  
>  	if (!test_opt(sbi, BG_GC))
>  		return 0;
> @@ -101,7 +102,7 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
>  	sbi->gc_thread = gc_th;
>  	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
>  	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
> -				"f2fs_gc-%s", dev_name(sbi->sb->s_bdi->dev));
> +				"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
>  	if (IS_ERR(gc_th->f2fs_gc_task)) {
>  		kfree(gc_th);
>  		sbi->gc_thread = NULL;

-- 
Jaegeuk Kim
Samsung

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] f2fs: fix to name f2fs GC task as per partition instead of per device
  2013-02-06  4:41 ` Jaegeuk Kim
@ 2013-02-06  4:59   ` Namjae Jeon
  2013-02-06  9:21     ` Jaegeuk Kim
  0 siblings, 1 reply; 4+ messages in thread
From: Namjae Jeon @ 2013-02-06  4:59 UTC (permalink / raw)
  To: jaegeuk.kim
  Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel, Namjae Jeon,
	Amit Sahrawat

2013/2/6, Jaegeuk Kim <jaegeuk.kim@samsung.com>:
> Hi,
>
> How about this?
>
> 2013-02-05 (화), 23:24 +0900, Namjae Jeon:
>> From: Namjae Jeon <namjae.jeon@samsung.com>
>>
>> After the commit 2184ad190a79ae2b40b5f5db1fbde5c22db6d310, it allowed
>> for naming GC threads based on the device.
>> i.e., if we have F2FS formatted partition in different devices - we will
>> have their GC thread names after the device. But, when we have a case
>> like
>> 2 or more partitions on the same device having F2FS filesystem.
>> In that case we are not able to differentiate between the GC threads.
>> So, to differentiate at all possible levels we can use the major/minor of
>> the device to have unique identification in the name.
>>
>> Before patch:
>> root  9726  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:48]
>> root  9736  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:16]
>> root  9892  0.0  0.0  0  0 ?  S  14:33   0:00 [f2fs_gc-8:32]
>> root  9907  0.0  0.0  0  0 ?  S  14:34   0:00 [f2fs_gc-8:32]
>>
>> After Patch:
>> root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:18]
>> root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:19]
>> root  16806  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:34]
>> root  16817  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:52]
>>
>
> root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-sdb1]
> root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-sdb2]
>
> IMO, it would be better to describe like this.
> We can simply use bdevname(bdev, name), so if no objection, I'll rebase
> this patch with this.
> Please, give me your opinion.
> Thanks,
Hi Jaegeuk.

Although it is good opinion to have user friendly names in the task
list, but we cannot have such names.

Because, even though bdevname() will provide the correct string. But
there is a limitation from the task struct command length.
The Task struct allows for the name to be maximum of ‘16’ characters in length.
char comm[TASK_COMM_LEN];

/* Task command name length */
#define TASK_COMM_LEN 16
So, the task name would be truncated to ‘16’ characters.

In case like for MMC partitions where partition name can be like:
mmcblk0p18, the name would become f2fs_gc-mmcblk0p18 -> this will be
truncate to “f2fs_gc-mmcblk0p”

Let me know your opinion.
Thanks.
>
>
>> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
>> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
>> ---
>>  fs/f2fs/gc.c |    3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>> index 742135a..b0c1f8c 100644
>> --- a/fs/f2fs/gc.c
>> +++ b/fs/f2fs/gc.c
>> @@ -91,6 +91,7 @@ static int gc_thread_func(void *data)
>>  int start_gc_thread(struct f2fs_sb_info *sbi)
>>  {
>>  	struct f2fs_gc_kthread *gc_th;
>> +	dev_t dev = sbi->sb->s_bdev->bd_dev;
>>
>>  	if (!test_opt(sbi, BG_GC))
>>  		return 0;
>> @@ -101,7 +102,7 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
>>  	sbi->gc_thread = gc_th;
>>  	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
>>  	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
>> -				"f2fs_gc-%s", dev_name(sbi->sb->s_bdi->dev));
>> +				"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
>>  	if (IS_ERR(gc_th->f2fs_gc_task)) {
>>  		kfree(gc_th);
>>  		sbi->gc_thread = NULL;
>
> --
> Jaegeuk Kim
> Samsung
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] f2fs: fix to name f2fs GC task as per partition instead of per device
  2013-02-06  4:59   ` Namjae Jeon
@ 2013-02-06  9:21     ` Jaegeuk Kim
  0 siblings, 0 replies; 4+ messages in thread
From: Jaegeuk Kim @ 2013-02-06  9:21 UTC (permalink / raw)
  To: Namjae Jeon
  Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel, Namjae Jeon,
	Amit Sahrawat

[-- Attachment #1: Type: text/plain, Size: 3923 bytes --]

Hi,

2013-02-06 (수), 13:59 +0900, Namjae Jeon:
> 2013/2/6, Jaegeuk Kim <jaegeuk.kim@samsung.com>:
> > Hi,
> >
> > How about this?
> >
> > 2013-02-05 (화), 23:24 +0900, Namjae Jeon:
> >> From: Namjae Jeon <namjae.jeon@samsung.com>
> >>
> >> After the commit 2184ad190a79ae2b40b5f5db1fbde5c22db6d310, it allowed
> >> for naming GC threads based on the device.
> >> i.e., if we have F2FS formatted partition in different devices - we will
> >> have their GC thread names after the device. But, when we have a case
> >> like
> >> 2 or more partitions on the same device having F2FS filesystem.
> >> In that case we are not able to differentiate between the GC threads.
> >> So, to differentiate at all possible levels we can use the major/minor of
> >> the device to have unique identification in the name.
> >>
> >> Before patch:
> >> root  9726  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:48]
> >> root  9736  0.0  0.0  0  0 ?  S  14:32   0:00 [f2fs_gc-8:16]
> >> root  9892  0.0  0.0  0  0 ?  S  14:33   0:00 [f2fs_gc-8:32]
> >> root  9907  0.0  0.0  0  0 ?  S  14:34   0:00 [f2fs_gc-8:32]
> >>
> >> After Patch:
> >> root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:18]
> >> root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:19]
> >> root  16806  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:34]
> >> root  16817  0.0  0.0  0  0 ?  S  14:58   0:00 [f2fs_gc-8:52]
> >>
> >
> > root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-sdb1]
> > root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-sdb2]
> >
> > IMO, it would be better to describe like this.
> > We can simply use bdevname(bdev, name), so if no objection, I'll rebase
> > this patch with this.
> > Please, give me your opinion.
> > Thanks,
> Hi Jaegeuk.
> 
> Although it is good opinion to have user friendly names in the task
> list, but we cannot have such names.
> 
> Because, even though bdevname() will provide the correct string. But
> there is a limitation from the task struct command length.
> The Task struct allows for the name to be maximum of ‘16’ characters in length.
> char comm[TASK_COMM_LEN];
> 
> /* Task command name length */
> #define TASK_COMM_LEN 16
> So, the task name would be truncated to ‘16’ characters.
> 
> In case like for MMC partitions where partition name can be like:
> mmcblk0p18, the name would become f2fs_gc-mmcblk0p18 -> this will be
> truncate to “f2fs_gc-mmcblk0p”

Agreed.
Thank you for explanation. :)

> 
> Let me know your opinion.
> Thanks.
> >
> >
> >> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
> >> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
> >> ---
> >>  fs/f2fs/gc.c |    3 ++-
> >>  1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> >> index 742135a..b0c1f8c 100644
> >> --- a/fs/f2fs/gc.c
> >> +++ b/fs/f2fs/gc.c
> >> @@ -91,6 +91,7 @@ static int gc_thread_func(void *data)
> >>  int start_gc_thread(struct f2fs_sb_info *sbi)
> >>  {
> >>  	struct f2fs_gc_kthread *gc_th;
> >> +	dev_t dev = sbi->sb->s_bdev->bd_dev;
> >>
> >>  	if (!test_opt(sbi, BG_GC))
> >>  		return 0;
> >> @@ -101,7 +102,7 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
> >>  	sbi->gc_thread = gc_th;
> >>  	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
> >>  	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
> >> -				"f2fs_gc-%s", dev_name(sbi->sb->s_bdi->dev));
> >> +				"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
> >>  	if (IS_ERR(gc_th->f2fs_gc_task)) {
> >>  		kfree(gc_th);
> >>  		sbi->gc_thread = NULL;
> >
> > --
> > Jaegeuk Kim
> > Samsung
> >
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Jaegeuk Kim
Samsung

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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-02-06  9:22 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-02-05 14:24 [PATCH] f2fs: fix to name f2fs GC task as per partition instead of per device Namjae Jeon
2013-02-06  4:41 ` Jaegeuk Kim
2013-02-06  4:59   ` Namjae Jeon
2013-02-06  9:21     ` Jaegeuk Kim

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