Re: [PATCH] xfs: more info from kmem deadlocks and high-level error msgs

[Carlos Maiolino <cmaiolino@redhat.com>]

On Fri, Oct 09, 2015 at 10:24:37PM -0500, Eric Sandeen wrote:
> In an effort to get more useful out of "possible memory
> allocation deadlock" messages, print the size of the
> requested allocation, and dump the stack if the xfs error
> level is tuned high.
> 
> The stack dump is implemented in define_xfs_printk_level()
> for error levels >= LOGLEVEL_ERR, partly because it
> seems generically useful, and also because kmem.c has
> no knowledge of xfs error level tunables or other such bits,
> it's very kmem-specific.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Looks good to me:

Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
> ---
> 
> diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
> index a7a3a63..dfe3a8b 100644
> --- a/fs/xfs/kmem.c
> +++ b/fs/xfs/kmem.c
> @@ -55,8 +55,8 @@ kmem_alloc(size_t size, xfs_km_flags_t flags)
>  			return ptr;
>  		if (!(++retries % 100))
>  			xfs_err(NULL,
> -		"possible memory allocation deadlock in %s (mode:0x%x)",
> -					__func__, lflags);
> +		"possible memory allocation deadlock size %u in %s (mode:0x%x)",
> +					(unsigned int)size, __func__, lflags);
>  		congestion_wait(BLK_RW_ASYNC, HZ/50);
>  	} while (1);
>  }
> diff --git a/fs/xfs/xfs_message.c b/fs/xfs/xfs_message.c
> index d8b6754..11792d8 100644
> --- a/fs/xfs/xfs_message.c
> +++ b/fs/xfs/xfs_message.c
> @@ -17,6 +17,7 @@
>  
>  #include "xfs.h"
>  #include "xfs_fs.h"
> +#include "xfs_error.h"
>  #include "xfs_format.h"
>  #include "xfs_log_format.h"
>  #include "xfs_trans_resv.h"
> @@ -43,6 +44,7 @@ void func(const struct xfs_mount *mp, const char *fmt, ...)	\
>  {								\
>  	struct va_format	vaf;				\
>  	va_list			args;				\
> +	int			level;				\
>  								\
>  	va_start(args, fmt);					\
>  								\
> @@ -51,6 +53,11 @@ void func(const struct xfs_mount *mp, const char *fmt, ...)	\
>  								\
>  	__xfs_printk(kern_level, mp, &vaf);			\
>  	va_end(args);						\
> +								\
> +	if (!kstrtoint(kern_level, 0, &level) &&		\
> +	    level <= LOGLEVEL_ERR &&				\
> +	    xfs_error_level >= XFS_ERRLEVEL_HIGH)		\
> +		xfs_stack_trace();				\
>  }								\
>  
>  define_xfs_printk_level(xfs_emerg, KERN_EMERG);
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

-- 
Carlos

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