From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753077AbeBKKgs (ORCPT ); Sun, 11 Feb 2018 05:36:48 -0500 Received: from forwardcorp1g.cmail.yandex.net ([87.250.241.190]:56903 "EHLO forwardcorp1g.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752790AbeBKKgr (ORCPT ); Sun, 11 Feb 2018 05:36:47 -0500 Authentication-Results: smtpcorp1o.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Subject: [PATCH] proc/kpageflags: add KPF_WAITERS From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Naoya Horiguchi , Michal Hocko , Linus Torvalds , "Kirill A. Shutemov" , Nicholas Piggin Date: Sun, 11 Feb 2018 13:36:41 +0300 Message-ID: <151834540184.176427.12174649162560874101.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KPF_WAITERS indicates tasks are waiting for a page lock or writeback. This might be false-positive, in this case next unlock will clear it. This looks like worth information not only for kernel hacking. In tool page-types in non-raw mode treat KPF_WAITERS without KPF_LOCKED and KPF_WRITEBACK as false-positive and hide it. Signed-off-by: Konstantin Khlebnikov --- fs/proc/page.c | 1 + include/uapi/linux/kernel-page-flags.h | 1 + tools/vm/page-types.c | 7 +++++++ 3 files changed, 9 insertions(+) diff --git a/fs/proc/page.c b/fs/proc/page.c index 1491918a33c3..b9312e1124af 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -159,6 +159,7 @@ u64 stable_page_flags(struct page *page) u |= 1 << KPF_IDLE; u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked); + u |= kpf_copy_bit(k, KPF_WAITERS, PG_waiters); u |= kpf_copy_bit(k, KPF_SLAB, PG_slab); if (PageTail(page) && PageSlab(compound_head(page))) diff --git a/include/uapi/linux/kernel-page-flags.h b/include/uapi/linux/kernel-page-flags.h index fa139841ec18..1118a028f2b3 100644 --- a/include/uapi/linux/kernel-page-flags.h +++ b/include/uapi/linux/kernel-page-flags.h @@ -35,6 +35,7 @@ #define KPF_BALLOON 23 #define KPF_ZERO_PAGE 24 #define KPF_IDLE 25 +#define KPF_WAITERS 26 #endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */ diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c index a8783f48f77f..76d880b768b5 100644 --- a/tools/vm/page-types.c +++ b/tools/vm/page-types.c @@ -107,6 +107,7 @@ static const char * const page_flag_names[] = { [KPF_LOCKED] = "L:locked", + [KPF_WAITERS] = "Q:waiters", [KPF_ERROR] = "E:error", [KPF_REFERENCED] = "R:referenced", [KPF_UPTODATE] = "U:uptodate", @@ -498,6 +499,12 @@ static uint64_t well_known_flags(uint64_t flags) if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE))) flags &= ~BITS_COMPOUND; + /* Treat WAITERS without LOCKED or WRITEBACK as false-postive */ + if ((flags & (BIT(WAITERS) | + BIT(LOCKED) | + BIT(WRITEBACK))) == BIT(WAITERS)) + flags &= ~BIT(WAITERS); + return flags; }