Re: [PATCH] mm: memory-failure: convert to pr_fmt()

["HORIGUCHI NAOYA(堀口 直也)" <naoya.horiguchi@nec.com>]

On Tue, Jul 26, 2022 at 04:10:46PM +0800, Kefeng Wang wrote:
> Use pr_fmt to prefix pr_<level> output.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

There're other classes of prefixes like "Unpoison:" and "soft offline:" in
mm/memory-failure.c.  So simply adding subsystem-wide pr_fmt() changes to
print out two prefixes like below:

  [ 1479.892348] Memory failure: soft offline: 0x1b8200: page migration failed 1, type 0x57ffffc00a000c(uptodate|dirty|mappedtodisk|swapbacked|node=1|zone=2|lastcpupid=0x1fffff)

  [ 1486.871130] Memory failure: Unpoison: Software-unpoisoned page 0x14f00

Do you intend this change?

Thanks,
Naoya Horiguchi

> ---
> The patch is based on next-20220725.
> 
>  mm/memory-failure.c | 56 +++++++++++++++++++++------------------------
>  1 file changed, 26 insertions(+), 30 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 2bc1a47c3d46..f0e1961d4482 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -33,6 +33,9 @@
>   * are rare we hope to get away with this. This avoids impacting the core 
>   * VM.
>   */
> +
> +#define pr_fmt(fmt) "Memory failure: " fmt
> +
>  #include <linux/kernel.h>
>  #include <linux/mm.h>
>  #include <linux/page-flags.h>
> @@ -258,7 +261,7 @@ static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags)
>  	short addr_lsb = tk->size_shift;
>  	int ret = 0;
>  
> -	pr_err("Memory failure: %#lx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
> +	pr_err("%#lx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
>  			pfn, t->comm, t->pid);
>  
>  	if ((flags & MF_ACTION_REQUIRED) && (t == current))
> @@ -276,7 +279,7 @@ static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags)
>  		ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr,
>  				      addr_lsb, t);  /* synchronous? */
>  	if (ret < 0)
> -		pr_info("Memory failure: Error sending signal to %s:%d: %d\n",
> +		pr_info("Error sending signal to %s:%d: %d\n",
>  			t->comm, t->pid, ret);
>  	return ret;
>  }
> @@ -358,7 +361,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
>  
>  	tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC);
>  	if (!tk) {
> -		pr_err("Memory failure: Out of memory while machine check handling\n");
> +		pr_err("Out of memory while machine check handling\n");
>  		return;
>  	}
>  
> @@ -385,7 +388,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
>  	 * has a mapping for the page.
>  	 */
>  	if (tk->addr == -EFAULT) {
> -		pr_info("Memory failure: Unable to find user space address %lx in %s\n",
> +		pr_info("Unable to find user space address %lx in %s\n",
>  			page_to_pfn(p), tsk->comm);
>  	} else if (tk->size_shift == 0) {
>  		kfree(tk);
> @@ -418,7 +421,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, bool fail,
>  			 * signal and then access the memory. Just kill it.
>  			 */
>  			if (fail || tk->addr == -EFAULT) {
> -				pr_err("Memory failure: %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
> +				pr_err("%#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
>  				       pfn, tk->tsk->comm, tk->tsk->pid);
>  				do_send_sig_info(SIGKILL, SEND_SIG_PRIV,
>  						 tk->tsk, PIDTYPE_PID);
> @@ -431,7 +434,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, bool fail,
>  			 * process anyways.
>  			 */
>  			else if (kill_proc(tk, pfn, flags) < 0)
> -				pr_err("Memory failure: %#lx: Cannot send advisory machine check signal to %s:%d\n",
> +				pr_err("%#lx: Cannot send advisory machine check signal to %s:%d\n",
>  				       pfn, tk->tsk->comm, tk->tsk->pid);
>  		}
>  		put_task_struct(tk->tsk);
> @@ -821,12 +824,10 @@ static int truncate_error_page(struct page *p, unsigned long pfn,
>  		int err = mapping->a_ops->error_remove_page(mapping, p);
>  
>  		if (err != 0) {
> -			pr_info("Memory failure: %#lx: Failed to punch page: %d\n",
> -				pfn, err);
> +			pr_info("%#lx: Failed to punch page: %d\n", pfn, err);
>  		} else if (page_has_private(p) &&
>  			   !try_to_release_page(p, GFP_NOIO)) {
> -			pr_info("Memory failure: %#lx: failed to release buffers\n",
> -				pfn);
> +			pr_info("%#lx: failed to release buffers\n", pfn);
>  		} else {
>  			ret = MF_RECOVERED;
>  		}
> @@ -838,8 +839,7 @@ static int truncate_error_page(struct page *p, unsigned long pfn,
>  		if (invalidate_inode_page(p))
>  			ret = MF_RECOVERED;
>  		else
> -			pr_info("Memory failure: %#lx: Failed to invalidate\n",
> -				pfn);
> +			pr_info("%#lx: Failed to invalidate\n",	pfn);
>  	}
>  
>  	return ret;
> @@ -869,7 +869,7 @@ static bool has_extra_refcount(struct page_state *ps, struct page *p,
>  		count -= 1;
>  
>  	if (count > 0) {
> -		pr_err("Memory failure: %#lx: %s still referenced by %d users\n",
> +		pr_err("%#lx: %s still referenced by %d users\n",
>  		       page_to_pfn(p), action_page_types[ps->type], count);
>  		return true;
>  	}
> @@ -893,7 +893,7 @@ static int me_kernel(struct page_state *ps, struct page *p)
>   */
>  static int me_unknown(struct page_state *ps, struct page *p)
>  {
> -	pr_err("Memory failure: %#lx: Unknown page state\n", page_to_pfn(p));
> +	pr_err("%#lx: Unknown page state\n", page_to_pfn(p));
>  	unlock_page(p);
>  	return MF_FAILED;
>  }
> @@ -1179,7 +1179,7 @@ static void action_result(unsigned long pfn, enum mf_action_page_type type,
>  	trace_memory_failure_event(pfn, type, result);
>  
>  	num_poisoned_pages_inc();
> -	pr_err("Memory failure: %#lx: recovery action for %s: %s\n",
> +	pr_err("%#lx: recovery action for %s: %s\n",
>  		pfn, action_page_types[type], action_name[result]);
>  }
>  
> @@ -1254,8 +1254,7 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags)
>  		if (head == compound_head(page))
>  			return 1;
>  
> -		pr_info("Memory failure: %#lx cannot catch tail\n",
> -			page_to_pfn(page));
> +		pr_info("%#lx cannot catch tail\n", page_to_pfn(page));
>  		put_page(head);
>  	}
>  
> @@ -1318,7 +1317,7 @@ static int get_any_page(struct page *p, unsigned long flags)
>  	}
>  out:
>  	if (ret == -EIO)
> -		pr_err("Memory failure: %#lx: unhandlable page.\n", page_to_pfn(p));
> +		pr_err("%#lx: unhandlable page.\n", page_to_pfn(p));
>  
>  	return ret;
>  }
> @@ -1417,13 +1416,12 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
>  		return true;
>  
>  	if (PageKsm(p)) {
> -		pr_err("Memory failure: %#lx: can't handle KSM pages.\n", pfn);
> +		pr_err("%#lx: can't handle KSM pages.\n", pfn);
>  		return false;
>  	}
>  
>  	if (PageSwapCache(p)) {
> -		pr_err("Memory failure: %#lx: keeping poisoned page in swap cache\n",
> -			pfn);
> +		pr_err("%#lx: keeping poisoned page in swap cache\n", pfn);
>  		ttu |= TTU_IGNORE_HWPOISON;
>  	}
>  
> @@ -1441,7 +1439,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
>  		} else {
>  			kill = 0;
>  			ttu |= TTU_IGNORE_HWPOISON;
> -			pr_info("Memory failure: %#lx: corrupted page was clean: dropped without side effects\n",
> +			pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
>  				pfn);
>  		}
>  	}
> @@ -1470,14 +1468,14 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
>  			try_to_unmap(folio, ttu|TTU_RMAP_LOCKED);
>  			i_mmap_unlock_write(mapping);
>  		} else
> -			pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
> +			pr_info("%#lx: could not lock mapping for mapped huge page\n", pfn);
>  	} else {
>  		try_to_unmap(folio, ttu);
>  	}
>  
>  	unmap_success = !page_mapped(hpage);
>  	if (!unmap_success)
> -		pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
> +		pr_err("%#lx: failed to unmap page (mapcount=%d)\n",
>  		       pfn, page_mapcount(hpage));
>  
>  	/*
> @@ -1844,7 +1842,7 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb
>  		*hugetlb = 0;
>  		return 0;
>  	} else if (res == -EHWPOISON) {
> -		pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn);
> +		pr_err("%#lx: already hardware poisoned\n", pfn);
>  		if (flags & MF_ACTION_REQUIRED) {
>  			head = compound_head(p);
>  			res = kill_accessing_process(current, page_to_pfn(head), flags);
> @@ -2003,8 +2001,7 @@ int memory_failure(unsigned long pfn, int flags)
>  				goto unlock_mutex;
>  			}
>  		}
> -		pr_err("Memory failure: %#lx: memory outside kernel control\n",
> -			pfn);
> +		pr_err("%#lx: memory outside kernel control\n", pfn);
>  		res = -ENXIO;
>  		goto unlock_mutex;
>  	}
> @@ -2015,8 +2012,7 @@ int memory_failure(unsigned long pfn, int flags)
>  		goto unlock_mutex;
>  
>  	if (TestSetPageHWPoison(p)) {
> -		pr_err("Memory failure: %#lx: already hardware poisoned\n",
> -			pfn);
> +		pr_err("%#lx: already hardware poisoned\n", pfn);
>  		res = -EHWPOISON;
>  		if (flags & MF_ACTION_REQUIRED)
>  			res = kill_accessing_process(current, pfn, flags);
> @@ -2232,7 +2228,7 @@ void memory_failure_queue(unsigned long pfn, int flags)
>  	if (kfifo_put(&mf_cpu->fifo, entry))
>  		schedule_work_on(smp_processor_id(), &mf_cpu->work);
>  	else
> -		pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n",
> +		pr_err("buffer overflow when queuing memory failure at %#lx\n",
>  		       pfn);
>  	spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
>  	put_cpu_var(memory_failure_cpu);
> -- 
> 2.35.3