| Message ID | 153074045526.27838.11460088022513024933.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 04, 2018 at 02:40:55PM -0700, Dan Williams wrote: > In preparation for supporting memory_failure() for dax mappings, teach > collect_procs() to also determine the mapping size. Unlike typical > mappings the dax mapping size is determined by walking page-table > entries rather than using the compound-page accounting for THP pages. > > Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Looks good to me. Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > --- > mm/memory-failure.c | 81 +++++++++++++++++++++++++-------------------------- > 1 file changed, 40 insertions(+), 41 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 9d142b9b86dc..4d70753af59c 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -174,22 +174,51 @@ int hwpoison_filter(struct page *p) > EXPORT_SYMBOL_GPL(hwpoison_filter); > > /* > + * Kill all processes that have a poisoned page mapped and then isolate > + * the page. > + * > + * General strategy: > + * Find all processes having the page mapped and kill them. > + * But we keep a page reference around so that the page is not > + * actually freed yet. > + * Then stash the page away > + * > + * There's no convenient way to get back to mapped processes > + * from the VMAs. So do a brute-force search over all > + * running processes. > + * > + * Remember that machine checks are not common (or rather > + * if they are common you have other problems), so this shouldn't > + * be a performance issue. > + * > + * Also there are some races possible while we get from the > + * error detection to actually handle it. > + */ > + > +struct to_kill { > + struct list_head nd; > + struct task_struct *tsk; > + unsigned long addr; > + short size_shift; > + char addr_valid; > +}; > + > +/* > * Send all the processes who have the page mapped a signal. > * ``action optional'' if they are not immediately affected by the error > * ``action required'' if error happened in current execution context > */ > -static int kill_proc(struct task_struct *t, unsigned long addr, > - unsigned long pfn, struct page *page, int flags) > +static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags) > { > - short addr_lsb; > + struct task_struct *t = tk->tsk; > + short addr_lsb = tk->size_shift; > int ret; > > pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory corruption\n", > pfn, t->comm, t->pid); > - addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT; > > if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) { > - ret = force_sig_mceerr(BUS_MCEERR_AR, (void __user *)addr, > + ret = force_sig_mceerr(BUS_MCEERR_AR, (void __user *)tk->addr, > addr_lsb, current); > } else { > /* > @@ -198,7 +227,7 @@ static int kill_proc(struct task_struct *t, unsigned long addr, > * This could cause a loop when the user sets SIGBUS > * to SIG_IGN, but hopefully no one will do that? > */ > - ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)addr, > + ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr, > addr_lsb, t); /* synchronous? */ > } > if (ret < 0) > @@ -235,35 +264,6 @@ void shake_page(struct page *p, int access) > EXPORT_SYMBOL_GPL(shake_page); > > /* > - * Kill all processes that have a poisoned page mapped and then isolate > - * the page. > - * > - * General strategy: > - * Find all processes having the page mapped and kill them. > - * But we keep a page reference around so that the page is not > - * actually freed yet. > - * Then stash the page away > - * > - * There's no convenient way to get back to mapped processes > - * from the VMAs. So do a brute-force search over all > - * running processes. > - * > - * Remember that machine checks are not common (or rather > - * if they are common you have other problems), so this shouldn't > - * be a performance issue. > - * > - * Also there are some races possible while we get from the > - * error detection to actually handle it. > - */ > - > -struct to_kill { > - struct list_head nd; > - struct task_struct *tsk; > - unsigned long addr; > - char addr_valid; > -}; > - > -/* > * Failure handling: if we can't find or can't kill a process there's > * not much we can do. We just print a message and ignore otherwise. > */ > @@ -292,6 +292,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, > } > tk->addr = page_address_in_vma(p, vma); > tk->addr_valid = 1; > + tk->size_shift = compound_order(compound_head(p)) + PAGE_SHIFT; > > /* > * In theory we don't have to kill when the page was > @@ -317,9 +318,8 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, > * Also when FAIL is set do a force kill because something went > * wrong earlier. > */ > -static void kill_procs(struct list_head *to_kill, int forcekill, > - bool fail, struct page *page, unsigned long pfn, > - int flags) > +static void kill_procs(struct list_head *to_kill, int forcekill, bool fail, > + unsigned long pfn, int flags) > { > struct to_kill *tk, *next; > > @@ -342,8 +342,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, > * check for that, but we need to tell the > * process anyways. > */ > - else if (kill_proc(tk->tsk, tk->addr, > - pfn, page, flags) < 0) > + else if (kill_proc(tk, pfn, flags) < 0) > pr_err("Memory failure: %#lx: Cannot send advisory machine check signal to %s:%d\n", > pfn, tk->tsk->comm, tk->tsk->pid); > } > @@ -1012,7 +1011,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, > * any accesses to the poisoned memory. > */ > forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL); > - kill_procs(&tokill, forcekill, !unmap_success, p, pfn, flags); > + kill_procs(&tokill, forcekill, !unmap_success, pfn, flags); > > return unmap_success; > } > >
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 9d142b9b86dc..4d70753af59c 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -174,22 +174,51 @@ int hwpoison_filter(struct page *p) EXPORT_SYMBOL_GPL(hwpoison_filter); /* + * Kill all processes that have a poisoned page mapped and then isolate + * the page. + * + * General strategy: + * Find all processes having the page mapped and kill them. + * But we keep a page reference around so that the page is not + * actually freed yet. + * Then stash the page away + * + * There's no convenient way to get back to mapped processes + * from the VMAs. So do a brute-force search over all + * running processes. + * + * Remember that machine checks are not common (or rather + * if they are common you have other problems), so this shouldn't + * be a performance issue. + * + * Also there are some races possible while we get from the + * error detection to actually handle it. + */ + +struct to_kill { + struct list_head nd; + struct task_struct *tsk; + unsigned long addr; + short size_shift; + char addr_valid; +}; + +/* * Send all the processes who have the page mapped a signal. * ``action optional'' if they are not immediately affected by the error * ``action required'' if error happened in current execution context */ -static int kill_proc(struct task_struct *t, unsigned long addr, - unsigned long pfn, struct page *page, int flags) +static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags) { - short addr_lsb; + struct task_struct *t = tk->tsk; + short addr_lsb = tk->size_shift; int ret; pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory corruption\n", pfn, t->comm, t->pid); - addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT; if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) { - ret = force_sig_mceerr(BUS_MCEERR_AR, (void __user *)addr, + ret = force_sig_mceerr(BUS_MCEERR_AR, (void __user *)tk->addr, addr_lsb, current); } else { /* @@ -198,7 +227,7 @@ static int kill_proc(struct task_struct *t, unsigned long addr, * This could cause a loop when the user sets SIGBUS * to SIG_IGN, but hopefully no one will do that? */ - ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)addr, + ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr, addr_lsb, t); /* synchronous? */ } if (ret < 0) @@ -235,35 +264,6 @@ void shake_page(struct page *p, int access) EXPORT_SYMBOL_GPL(shake_page); /* - * Kill all processes that have a poisoned page mapped and then isolate - * the page. - * - * General strategy: - * Find all processes having the page mapped and kill them. - * But we keep a page reference around so that the page is not - * actually freed yet. - * Then stash the page away - * - * There's no convenient way to get back to mapped processes - * from the VMAs. So do a brute-force search over all - * running processes. - * - * Remember that machine checks are not common (or rather - * if they are common you have other problems), so this shouldn't - * be a performance issue. - * - * Also there are some races possible while we get from the - * error detection to actually handle it. - */ - -struct to_kill { - struct list_head nd; - struct task_struct *tsk; - unsigned long addr; - char addr_valid; -}; - -/* * Failure handling: if we can't find or can't kill a process there's * not much we can do. We just print a message and ignore otherwise. */ @@ -292,6 +292,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, } tk->addr = page_address_in_vma(p, vma); tk->addr_valid = 1; + tk->size_shift = compound_order(compound_head(p)) + PAGE_SHIFT; /* * In theory we don't have to kill when the page was @@ -317,9 +318,8 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, * Also when FAIL is set do a force kill because something went * wrong earlier. */ -static void kill_procs(struct list_head *to_kill, int forcekill, - bool fail, struct page *page, unsigned long pfn, - int flags) +static void kill_procs(struct list_head *to_kill, int forcekill, bool fail, + unsigned long pfn, int flags) { struct to_kill *tk, *next; @@ -342,8 +342,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, * check for that, but we need to tell the * process anyways. */ - else if (kill_proc(tk->tsk, tk->addr, - pfn, page, flags) < 0) + else if (kill_proc(tk, pfn, flags) < 0) pr_err("Memory failure: %#lx: Cannot send advisory machine check signal to %s:%d\n", pfn, tk->tsk->comm, tk->tsk->pid); } @@ -1012,7 +1011,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, * any accesses to the poisoned memory. */ forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL); - kill_procs(&tokill, forcekill, !unmap_success, p, pfn, flags); + kill_procs(&tokill, forcekill, !unmap_success, pfn, flags); return unmap_success; }
In preparation for supporting memory_failure() for dax mappings, teach collect_procs() to also determine the mapping size. Unlike typical mappings the dax mapping size is determined by walking page-table entries rather than using the compound-page accounting for THP pages. Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- mm/memory-failure.c | 81 +++++++++++++++++++++++++-------------------------- 1 file changed, 40 insertions(+), 41 deletions(-)