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

From: HORIGUCHI NAOYA(堀口 直也)
Date: Tue Jul 26 2022 - 21:12:16 EST


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@xxxxxxxxxx>

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