Messages in this thread | | | Subject | Re: [PATCH] mm, soft-offline: convert parameter to pfn | From | David Hildenbrand <> | Date | Thu, 17 Oct 2019 10:02:55 +0200 |
| |
On 17.10.19 09:50, Naoya Horiguchi wrote: > On Thu, Oct 17, 2019 at 09:16:42AM +0200, David Hildenbrand wrote: >> On 17.10.19 01:47, Naoya Horiguchi wrote: >>> On Wed, Oct 16, 2019 at 10:57:57AM +0200, David Hildenbrand wrote: >>>> On 16.10.19 10:54, Naoya Horiguchi wrote: >>>>> On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote: >>>>>> On 16.10.19 10:27, Naoya Horiguchi wrote: >>>>>>> On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote: >>>>>>>> On 16.10.19 09:09, Naoya Horiguchi wrote: >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> I wrote a simple cleanup for parameter of soft_offline_page(), >>>>>>>>> based on thread https://lkml.org/lkml/2019/10/11/57. >>>>>>>>> >>>>>>>>> I know that we need more cleanup on hwpoison-inject, but I think >>>>>>>>> that will be mentioned in re-write patchset Oscar is preparing now. >>>>>>>>> So let me shared only this part as a separate one now. >>>>>>> ... >>>>>>>> >>>>>>>> I think you should rebase that patch on linux-next (where the >>>>>>>> pfn_to_online_page() check is in place). I assume you'll want to move the >>>>>>>> pfn_to_online_page() check into soft_offline_page() then as well? >>>>>>> >>>>>>> I rebased to next-20191016. And yes, we will move pfn_to_online_page() >>>>>>> into soft offline code. It seems that we can also move pfn_valid(), >>>>>>> but is simply moving like below good enough for you? >>>>>> >>>>>> At least I can't am the patch to current next/master (due to >>>>>> pfn_to_online_page()). >>>> >>>> Could also be that my "git am" skills failed as the mail was not a >>>> proper patch itself :) >>> >>> Sorry for the inconvenience, my company email system breaks original >>> message by introducing quoted-printable format ('=20' or '=3D'). >>> Most mail client usually handles it but git-am doesn't. >>> I give up using it and send via smtp.gmail.com. >>> >>>>> @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page) >>>>> * This is not a 100% solution for all memory, but tries to be >>>>> * ``good enough'' for the majority of memory. >>>>> */ >>>>> -int soft_offline_page(struct page *page, int flags) >>>>> +int soft_offline_page(unsigned long pfn, int flags) >>>>> { >>>>> int ret; >>>>> - unsigned long pfn = page_to_pfn(page); >>>>> + struct page *page; >>>>> + if (!pfn_valid(pfn)) >>>>> + return -ENXIO; >>>>> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ >>>>> + page = pfn_to_online_page(pfn); >>>>> + if (!page) >>>>> + return -EIO; >>>>> if (is_zone_device_page(page)) { >>>> >>>> -> this is now no longer possible! So you can drop the whole if >>>> (is_zone_device....) case >>> >>> OK, thanks. I updated it. >>> >>> Thanks, >>> Naoya Horiguchi >>> --- >>> From 5faf227839b578726fe7f5ff414a153abb3b3a31 Mon Sep 17 00:00:00 2001 >>> From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> >>> Date: Thu, 17 Oct 2019 08:40:53 +0900 >>> Subject: [PATCH] mm, soft-offline: convert parameter to pfn >>> >>> Currently soft_offline_page() receives struct page, and its sibling >>> memory_failure() receives pfn. This discrepancy looks weird and makes >>> precheck on pfn validity tricky. So let's align them. >>> >>> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> >>> --- >>> drivers/base/memory.c | 7 +------ >>> include/linux/mm.h | 2 +- >>> mm/madvise.c | 2 +- >>> mm/memory-failure.c | 19 +++++++++---------- >>> 4 files changed, 12 insertions(+), 18 deletions(-) >>> >>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >>> index 55907c27075b..a757d9ed88a7 100644 >>> --- a/drivers/base/memory.c >>> +++ b/drivers/base/memory.c >>> @@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev, >>> if (kstrtoull(buf, 0, &pfn) < 0) >>> return -EINVAL; >>> pfn >>= PAGE_SHIFT; >>> - if (!pfn_valid(pfn)) >>> - return -ENXIO; >>> - /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ >>> - if (!pfn_to_online_page(pfn)) >>> - return -EIO; >>> - ret = soft_offline_page(pfn_to_page(pfn), 0); >>> + ret = soft_offline_page(pfn, 0); >>> return ret == 0 ? count : ret; >>> } >>> diff --git a/include/linux/mm.h b/include/linux/mm.h >>> index 44d058723db9..fd360d208346 100644 >>> --- a/include/linux/mm.h >>> +++ b/include/linux/mm.h >>> @@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill; >>> extern int sysctl_memory_failure_recovery; >>> extern void shake_page(struct page *p, int access); >>> extern atomic_long_t num_poisoned_pages __read_mostly; >>> -extern int soft_offline_page(struct page *page, int flags); >>> +extern int soft_offline_page(unsigned long pfn, int flags); >>> /* >>> diff --git a/mm/madvise.c b/mm/madvise.c >>> index 2be9f3fdb05e..99dd06fecfa9 100644 >>> --- a/mm/madvise.c >>> +++ b/mm/madvise.c >>> @@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior, >>> pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", >>> pfn, start); >>> - ret = soft_offline_page(page, MF_COUNT_INCREASED); >>> + ret = soft_offline_page(pfn, MF_COUNT_INCREASED); >>> if (ret) >>> return ret; >>> continue; >>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>> index 05c8c6df25e6..af2712004a4d 100644 >>> --- a/mm/memory-failure.c >>> +++ b/mm/memory-failure.c >>> @@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work) >>> if (!gotten) >>> break; >>> if (entry.flags & MF_SOFT_OFFLINE) >>> - soft_offline_page(pfn_to_page(entry.pfn), entry.flags); >>> + soft_offline_page(entry.pfn, entry.flags); >>> else >>> memory_failure(entry.pfn, entry.flags); >>> } >>> @@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page) >>> /** >>> * soft_offline_page - Soft offline a page. >>> - * @page: page to offline >>> + * @pfn: pfn to soft-offline >>> * @flags: flags. Same as memory_failure(). >>> * >>> * Returns 0 on success, otherwise negated errno. >>> @@ -1877,18 +1877,17 @@ static int soft_offline_free_page(struct page *page) >>> * This is not a 100% solution for all memory, but tries to be >>> * ``good enough'' for the majority of memory. >>> */ >>> -int soft_offline_page(struct page *page, int flags) >>> +int soft_offline_page(unsigned long pfn, int flags) >>> { >>> int ret; >>> - unsigned long pfn = page_to_pfn(page); >>> + struct page *page; >>> - if (is_zone_device_page(page)) { >>> - pr_debug_ratelimited("soft_offline: %#lx page is device page\n", >>> - pfn); >>> - if (flags & MF_COUNT_INCREASED) >>> - put_page(page); >>> + if (!pfn_valid(pfn)) >>> + return -ENXIO; >>> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ >>> + page = pfn_to_online_page(pfn); >>> + if (!page) >> >> If you pass in a PFN with MF_COUNT_INCREASED via mm/madvise.c, you would now >> no longer do a put_page(page) in case of ZONE_DEVICE (!page = >> pfn_to_online_page(pfn);) > > Yes, right. > >> >> something like this >> >> page = pfn_to_online_page(pfn); >> if (!page) { >> /* >> * With MF_COUNT_INCREASED, we can use pfn_to_page() directly >> * (esp., ZONE_DEVICE). >> */ >> if (flags & MF_COUNT_INCREASED) >> put_page(pfn_to_page(page)); >> return -EIO; >> } >> >> For !pfn_valid(pfn), this is not relevant. > > Actually I guess that !pfn_valid() never happens when called from > madvise_inject_error(), because madvise_inject_error() gets pfn via > get_user_pages_fast() which only returns valid page for valid pfn. > > And we plan to remove MF_COUNT_INCREASED by Oscar's re-design work, > so I start feeling that this patch should come on top of his tree.
I agree, let's clean that up first.
--
Thanks,
David / dhildenb
| |