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From: Rusty Russell <rusty@rustcorp.com.au>
To: Tejun Heo <tj@kernel.org>, akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 01/32] cpumask: always use nr_cpu_ids in formatting and parsing functions
Date: Tue, 27 Jan 2015 10:12:20 +1030	[thread overview]
Message-ID: <87fvaxrtwj.fsf@rustcorp.com.au> (raw)
In-Reply-To: <1422108218-25398-2-git-send-email-tj@kernel.org>

Tejun Heo <tj@kernel.org> writes:
> Currently, the formatting and parsing functions in cpumask.h use
> nr_cpumask_bits like other cpumask functions; however, nr_cpumask_bits
> is either NR_CPUS or nr_cpu_ids depending on CONFIG_CPUMASK_OFFSTACK.
> This leads to inconsistent behaviors.

Acked-by: Rusty Russell <rusty@rustcorp.com.au>

Thanks!
Rusty.


>
> With CONFIG_NR_CPUS=512 and !CONFIG_CPUMASK_OFFSTACK
>
>   # cat /sys/devices/virtual/net/lo/queues/rx-0/rps_cpus
>   00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000
>   # cat /proc/self/status | grep Cpus_allowed:
>   Cpus_allowed:   f
>
> With CONFIG_NR_CPUS=1024 and CONFIG_CPUMASK_OFFSTACK (fedora default)
>
>   # cat /sys/devices/virtual/net/lo/queues/rx-0/rps_cpus
>   0
>   # cat /proc/self/status | grep Cpus_allowed:
>   Cpus_allowed:   f
>
> Note that /proc/self/status is always using nr_cpu_ids regardless of
> config.  This is because seq cpumask formattings functions always use
> nr_cpu_ids.
>
> Given that the same output fields may switch between the two forms,
> converging on nr_cpu_ids always isn't too likely to surprise userland.
> This patch updates the formatting and parsing functions in cpumask.h
> to always use nr_cpu_ids.  There's no point in dealing with CPUs which
> aren't even possible on the machine.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Rusty Russell <rusty@rustcorp.com.au>
> ---
> Hello,
>
> Linus, this is the first of the three pre-requisite patches to convert
> the users of the dedicated bitmap formatting functions over to
> '%*pb[l]' formatting.
>
> If this approach is agreed upon, I think it'd be best to route these
> three patches through mainline soon so that subsystem conversion
> patches can pull these in and apply per-subsystem conversion patches.
>
> Thanks.
>
>  include/linux/cpumask.h | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
> index b950e9d..98939d1 100644
> --- a/include/linux/cpumask.h
> +++ b/include/linux/cpumask.h
> @@ -550,7 +550,7 @@ static inline void cpumask_copy(struct cpumask *dstp,
>  static inline int cpumask_scnprintf(char *buf, int len,
>  				    const struct cpumask *srcp)
>  {
> -	return bitmap_scnprintf(buf, len, cpumask_bits(srcp), nr_cpumask_bits);
> +	return bitmap_scnprintf(buf, len, cpumask_bits(srcp), nr_cpu_ids);
>  }
>  
>  /**
> @@ -564,7 +564,7 @@ static inline int cpumask_scnprintf(char *buf, int len,
>  static inline int cpumask_parse_user(const char __user *buf, int len,
>  				     struct cpumask *dstp)
>  {
> -	return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
> +	return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpu_ids);
>  }
>  
>  /**
> @@ -579,7 +579,7 @@ static inline int cpumask_parselist_user(const char __user *buf, int len,
>  				     struct cpumask *dstp)
>  {
>  	return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
> -							nr_cpumask_bits);
> +				     nr_cpu_ids);
>  }
>  
>  /**
> @@ -595,7 +595,7 @@ static inline int cpulist_scnprintf(char *buf, int len,
>  				    const struct cpumask *srcp)
>  {
>  	return bitmap_scnlistprintf(buf, len, cpumask_bits(srcp),
> -				    nr_cpumask_bits);
> +				    nr_cpu_ids);
>  }
>  
>  /**
> @@ -610,7 +610,7 @@ static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
>  	char *nl = strchr(buf, '\n');
>  	unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
>  
> -	return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
> +	return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpu_ids);
>  }
>  
>  /**
> @@ -622,7 +622,7 @@ static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
>   */
>  static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
>  {
> -	return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
> +	return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpu_ids);
>  }
>  
>  /**
> @@ -817,7 +817,7 @@ static inline ssize_t
>  cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
>  {
>  	return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
> -				      nr_cpumask_bits);
> +				      nr_cpu_ids);
>  }
>  
>  /*
> -- 
> 2.1.0

  reply	other threads:[~2015-01-27  0:38 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-24 14:03 [PATCHSET] bitmap, cpumask, nodemask: implement %*pb[l] to format bitmaps directly from printf family of functions Tejun Heo
2015-01-24 14:03 ` [PATCH 01/32] cpumask: always use nr_cpu_ids in formatting and parsing functions Tejun Heo
2015-01-26 23:42   ` Rusty Russell [this message]
2015-01-24 14:03 ` [PATCH 02/32] lib/vsprintf: implement bitmap printing through '%*pb[l]' Tejun Heo
2015-01-26 13:50   ` Peter Zijlstra
2015-01-24 14:03 ` [PATCH 03/32] cpumask, nodemask: implement cpumask/nodemask_pr_args() Tejun Heo
2015-01-24 14:03 ` [PATCH 04/32] bitmap: use %*pb[l] to print bitmaps including cpumasks and nodemasks Tejun Heo
2015-01-24 14:03 ` [PATCH 05/32] mips: " Tejun Heo
2015-01-24 14:03 ` [PATCH 06/32] powerpc: " Tejun Heo
2015-01-24 14:03 ` [PATCH 07/32] s390: " Tejun Heo
2015-01-26  9:17   ` Heiko Carstens
2015-01-24 14:03 ` [PATCH 08/32] tile: " Tejun Heo
2015-01-24 14:03 ` [PATCH 09/32] x86: " Tejun Heo
2015-01-24 14:03 ` [PATCH 10/32] ia64: " Tejun Heo
2015-01-24 14:03 ` [PATCH 11/32] xtensa: " Tejun Heo
2015-01-24 14:03 ` [PATCH 12/32] arm: " Tejun Heo
2015-01-24 14:03 ` [PATCH 13/32] cpuset: " Tejun Heo
2015-01-24 14:03 ` [PATCH 14/32] rcu: " Tejun Heo
2015-01-24 21:16   ` Paul E. McKenney
2015-01-24 14:03 ` [PATCH 15/32] sched: " Tejun Heo
2015-01-24 14:03 ` [PATCH 16/32] time: " Tejun Heo
2015-01-24 14:03 ` [PATCH 17/32] percpu: " Tejun Heo
2015-01-24 14:03 ` [PATCH 18/32] workqueue: use %*pb[l] to format " Tejun Heo
2015-01-24 14:03 ` [PATCH 19/32] tracing: use %*pb[l] to print " Tejun Heo
2015-01-24 14:03 ` [PATCH 20/32] net: " Tejun Heo
2015-01-27  8:07   ` David Miller
2015-01-24 14:03 ` [PATCH 21/32] wireless: " Tejun Heo
2015-03-02 15:14   ` Kalle Valo
2015-01-24 14:03 ` [PATCH 22/32] input: " Tejun Heo
2015-01-24 14:03 ` [PATCH 23/32] scsi: " Tejun Heo
2015-01-24 14:03 ` [PATCH 24/32] usb: " Tejun Heo
2015-01-25 12:45   ` Greg Kroah-Hartman
2015-01-24 14:03 ` [PATCH 25/32] drivers/base: " Tejun Heo
2015-01-25 13:22   ` Greg Kroah-Hartman
2015-01-24 14:03 ` [PATCH 26/32] slub: " Tejun Heo
2015-01-24 17:48   ` Christoph Lameter
2015-01-24 14:03 ` [PATCH 27/32] mm: " Tejun Heo
2015-01-24 14:03 ` [PATCH 28/32] padata: " Tejun Heo
2015-01-24 14:03 ` [PATCH 29/32] proc: " Tejun Heo
2015-01-24 14:03 ` [PATCH 30/32] irq: " Tejun Heo
2015-01-24 14:03 ` [PATCH 31/32] profile: " Tejun Heo
2015-01-24 14:03 ` [PATCH 32/32] bitmap, cpumask, nodemask: remove dedicated formatting functions Tejun Heo

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