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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mm/page_alloc: replace custom bad page ratelimiting logic Message-ID: References: <20260811172156.356053-1-pfalcato@suse.de> <20260811172156.356053-3-pfalcato@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260811172156.356053-3-pfalcato@suse.de> X-Rspam-User: X-Stat-Signature: b3i3uxqjc5w3mcy4uwfp4nwfkg3qsahb X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: B388AA000F X-HE-Tag: 1786629694-844478 X-HE-Meta: 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 b807hlno O9WNJIXG97UHJZ31l7etnhhaW37qVbDJqTMqMdlZYSaCpe7iPqg7aoQvcwdYfFiU9dBfylzokff2Orxq1RWh/VXli2Q8upJ357tXl/pAMqLHC+K447Js8w6soF0vm2ur9BzwpGUngJ/D6N0FeHzWDlDFfS4sdjdKJUzhxoJLUUZdmHSyhJGjrDrM4Cs8tM7FHynd246kbkCIm/N/3n0sgriQilyU3Z7rzgh8HtYSR/WzZ290p1SNxc7hzJg1WJfIbfjHHBmJJxsbJHZ2L+UkKj/V2lpFKTs7wm02G+IEZkQJDSCJU9pjUVCCL7gvgPissBF5j Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Aug 11, 2026 at 06:21:56PM +0100, Pedro Falcato wrote: > The current logic (allow up to $BURST prints per minute) can be entirely > replaced by the generic version in lib/ratelimit.c, used around the kernel. > > Do so. The only functional difference should be that the new logs will > read something like: > > KERN_WARNING "bad_page: %d callbacks suppressed\n", ... > > But that should be fine enough. > > Signed-off-by: Pedro Falcato LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) > --- > mm/page_alloc.c | 28 +++++----------------------- > 1 file changed, 5 insertions(+), 23 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 12fac9084c48..9ccfd87bc273 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -613,31 +613,13 @@ static inline bool __maybe_unused bad_range(struct zone *zone, struct page *page > } > #endif > > +/* Allow a burst of 60 reports per minute */ > +static DEFINE_RATELIMIT_STATE(bad_page_ratelimit, 60 * HZ, 60); > + > static void bad_page(struct page *page, const char *reason) > { > - static unsigned long resume; > - static unsigned long nr_shown; > - static unsigned long nr_unshown; > - > - /* > - * Allow a burst of 60 reports, then keep quiet for that minute; > - * or allow a steady drip of one report per second. > - */ > - if (nr_shown == 60) { > - if (time_before(jiffies, resume)) { > - nr_unshown++; > - goto out; > - } > - if (nr_unshown) { > - pr_alert( > - "BUG: Bad page state: %lu messages suppressed\n", > - nr_unshown); > - nr_unshown = 0; > - } > - nr_shown = 0; > - } > - if (nr_shown++ == 0) > - resume = jiffies + 60 * HZ; > + if (!__ratelimit(&bad_page_ratelimit)) > + goto out; > > pr_alert("BUG: Bad page state in process %s pfn:%05lx\n", > current->comm, page_to_pfn(page)); > -- > 2.55.0 > -- Cheers, Lorenzo