2009-01-10 00:14:56

by Randy Dunlap

Subject: Re: async: make async a command line option for now

On Sat, 10 Jan 2009 00:02:52 GMT Linux Kernel Mailing List wrote:

> Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cdb80f630be5cbc23d82331f24dc4704f75b64f4
> Commit: cdb80f630be5cbc23d82331f24dc4704f75b64f4
> Parent: b32714ba29358a688ef337d5297bf4bdc9f596dc
> Author: Arjan van de Ven <[email protected]>
> AuthorDate: Fri Jan 9 13:23:45 2009 -0800
> Committer: Arjan van de Ven <[email protected]>
> CommitDate: Fri Jan 9 13:23:45 2009 -0800
>
> async: make async a command line option for now
>
> ... and have it default off.
> This does allow people to work with it for testing.


Is this boot option documented anywhere or did you mean to
keep it hidden to all but inquiring minds?


> Signed-off-by: Arjan van de Ven <[email protected]>
> ---
> kernel/async.c | 16 ++++++++++++++--
> 1 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/async.c b/kernel/async.c
> index 64cc916..f286e9f 100644
> --- a/kernel/async.c
> +++ b/kernel/async.c
> @@ -65,6 +65,8 @@ static LIST_HEAD(async_pending);
> static LIST_HEAD(async_running);
> static DEFINE_SPINLOCK(async_lock);
>
> +static int async_enabled = 0;
> +
> struct async_entry {
> struct list_head list;
> async_cookie_t cookie;
> @@ -169,7 +171,7 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct l
> * If we're out of memory or if there's too much work
> * pending already, we execute synchronously.
> */
> - if (!entry || atomic_read(&entry_count) > MAX_WORK) {
> + if (!async_enabled || !entry || atomic_read(&entry_count) > MAX_WORK) {
> kfree(entry);
> spin_lock_irqsave(&async_lock, flags);
> newcookie = next_cookie++;
> @@ -316,8 +318,18 @@ static int async_manager_thread(void *unused)
>
> static int __init async_init(void)
> {
> - kthread_run(async_manager_thread, NULL, "async/mgr");
> + if (async_enabled)
> + kthread_run(async_manager_thread, NULL, "async/mgr");
> return 0;
> }
>
> +static int __init setup_async(char *str)
> +{
> + async_enabled = 1;
> + return 1;
> +}
> +
> +__setup("fastboot", setup_async);
> +
> +
> core_initcall(async_init);

---
~Randy

2009-01-10 00:31:19

by Arjan van de Ven

Subject: Re: async: make async a command line option for now

Randy Dunlap wrote:
> On Sat, 10 Jan 2009 00:02:52 GMT Linux Kernel Mailing List wrote:
>
>> Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cdb80f630be5cbc23d82331f24dc4704f75b64f4
>> Commit: cdb80f630be5cbc23d82331f24dc4704f75b64f4
>> Parent: b32714ba29358a688ef337d5297bf4bdc9f596dc
>> Author: Arjan van de Ven <[email protected]>
>> AuthorDate: Fri Jan 9 13:23:45 2009 -0800
>> Committer: Arjan van de Ven <[email protected]>
>> CommitDate: Fri Jan 9 13:23:45 2009 -0800
>>
>> async: make async a command line option for now
>>
>> ... and have it default off.
>> This does allow people to work with it for testing.
>
>
> Is this boot option documented anywhere or did you mean to
> keep it hidden to all but inquiring minds?
>
>

for now low visibility is good;
in fact once the feature stabilizes it'll flip the other way around,
at which point it does need to be documented.