From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6BB9C433EF for ; Mon, 10 Jan 2022 12:45:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245641AbiAJMpH (ORCPT ); Mon, 10 Jan 2022 07:45:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234404AbiAJMpE (ORCPT ); Mon, 10 Jan 2022 07:45:04 -0500 Received: from mail-yb1-xb36.google.com (mail-yb1-xb36.google.com [IPv6:2607:f8b0:4864:20::b36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBF7EC06173F for ; Mon, 10 Jan 2022 04:45:03 -0800 (PST) Received: by mail-yb1-xb36.google.com with SMTP id c6so35577906ybk.3 for ; Mon, 10 Jan 2022 04:45:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1P551vXMJtNOZg3UvulkEAqSICcinl0woD2ztefNS7o=; b=J8HT5LkxET+0mA/gLuJ/3I8tJ0L1dk9wNhAOo5DNNY42Isd7GnY4vVgeym1jIAII2B bvQt1mrEEzlsg5P4duvDpbkgIZRSJzSTr3LCqsRK2HjFvfLSwEYkMX0Z4EkSQkLeEmsS SMH1+FtPy+xbvVMMKNaUum/LkvsBs7FV0YOpMH0yap7J8BOTb2Xg3g8RGwxPhmEWnoYz tJfU3dJM2REGP9rRTf1HrXs19n529ELk+fOGcWZO3sNhJUi8k2Unc1m1lFXG6Mp9yPyz kNoKClvpJ8IAb2ZAOAKFZ80zAsEslE/hUTtJbsWl0wLarmgu4uW/Iw9Wc3Ik+LQ2rSFX GEiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1P551vXMJtNOZg3UvulkEAqSICcinl0woD2ztefNS7o=; b=J7rlk5TZ9Vre9KaLbHBAT2yg89LvnBQDJSCNbsend7EfDVEX/JdWPXo9cqarwpGen2 +z9SWp7WIpQ+CcdQzLUJtNd6/kRsWn+kQAwwkEyo0PvYZ2fbVcPFgwq+qWiJ6iEtt7HK GuA+rTDVRdSkFiqf1TGYyev2OXuCbMNuV7e+jBl/JS0NnTwBqHmJSbLC6kVl6xPvyQhh GVubdg8rchSNxfaPHOgt1AZ94nknVBBTTDbcT/CCU2d4pndRVGk8SLoV8hrHE4NnamZk bmi8lzeW7t02zRcQh15xuLbVC6pLTeg77+zzKQjPwoIk3tuV3x1/lAad8v4R4zH6q/5M P7jg== X-Gm-Message-State: AOAM532CoSM6kpOTily0L64QOMDta0+R1VsM9RJ69bUApZEOJG/9UpNN cUX9/UwUWXxyQdyTjHqzgoHfncScXkYBLxsB4AaEGm4rz39Gg0Z0 X-Google-Smtp-Source: ABdhPJycy2dWcyvhhb6q58G9qtGURkXbwLiSXEN+llTRHtfSBr0UI1jHi2mIcsMkEMzGfGjYnibJ42BIPjr7DUTTC8g= X-Received: by 2002:a05:6902:1106:: with SMTP id o6mr67371292ybu.89.1641818702890; Mon, 10 Jan 2022 04:45:02 -0800 (PST) MIME-Version: 1.0 References: <20210402055745.3690281-1-varmam@google.com> In-Reply-To: From: Manish Varma Date: Mon, 10 Jan 2022 18:14:51 +0530 Message-ID: Subject: Re: [PATCH v3] fs: Improve eventpoll logging to stop indicting timerfd To: Alexander Viro , Thomas Gleixner Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, kernel test robot , Kelly Rossmoyer , Vijay Nayak Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hello Alexander and Thomas, Friendly ping if you could share feedback (if any) to get this patch merged. Thanks, Manish On Tue, Jun 22, 2021 at 3:36 AM Manish Varma wrote: > > Hello Alexander and Thomas, > > Please share if you have any further feedback on this patch, or if > there's any other action required from my end to before this gets > merged. > > Thanks, > Manish > > On Thu, Apr 1, 2021 at 10:57 PM Manish Varma wrote: > > > > timerfd doesn't create any wakelocks, but eventpoll can. When it does, > > it names them after the underlying file descriptor, and since all > > timerfd file descriptors are named "[timerfd]" (which saves memory on > > systems like desktops with potentially many timerfd instances), all > > wakesources created as a result of using the eventpoll-on-timerfd idiom > > are called... "[timerfd]". > > > > However, it becomes impossible to tell which "[timerfd]" wakesource is > > affliated with which process and hence troubleshooting is difficult. > > > > This change addresses this problem by changing the way eventpoll > > wakesources are named: > > > > 1) the top-level per-process eventpoll wakesource is now named "epoll:P" > > (instead of just "eventpoll"), where P, is the PID of the creating > > process. > > 2) individual per-underlying-filedescriptor eventpoll wakesources are > > now named "epollitemN:P.F", where N is a unique ID token and P is PID > > of the creating process and F is the name of the underlying file > > descriptor. > > > > All together that should be splitted up into a change to eventpoll and > > timerfd (or other file descriptors). > > > > Reported-by: kernel test robot > > Co-developed-by: Kelly Rossmoyer > > Signed-off-by: Kelly Rossmoyer > > Signed-off-by: Manish Varma > > --- > > drivers/base/power/wakeup.c | 10 ++++++++-- > > fs/eventpoll.c | 10 ++++++++-- > > include/linux/pm_wakeup.h | 4 ++-- > > 3 files changed, 18 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c > > index 01057f640233..3628536c67a5 100644 > > --- a/drivers/base/power/wakeup.c > > +++ b/drivers/base/power/wakeup.c > > @@ -216,13 +216,19 @@ EXPORT_SYMBOL_GPL(wakeup_source_remove); > > /** > > * wakeup_source_register - Create wakeup source and add it to the list. > > * @dev: Device this wakeup source is associated with (or NULL if virtual). > > - * @name: Name of the wakeup source to register. > > + * @fmt: format string for the wakeup source name > > */ > > struct wakeup_source *wakeup_source_register(struct device *dev, > > - const char *name) > > + const char *fmt, ...) > > { > > struct wakeup_source *ws; > > int ret; > > + char name[128]; > > + va_list args; > > + > > + va_start(args, fmt); > > + vsnprintf(name, sizeof(name), fmt, args); > > + va_end(args); > > > > ws = wakeup_source_create(name); > > if (ws) { > > diff --git a/fs/eventpoll.c b/fs/eventpoll.c > > index 7df8c0fa462b..7c35987a8887 100644 > > --- a/fs/eventpoll.c > > +++ b/fs/eventpoll.c > > @@ -312,6 +312,7 @@ struct ctl_table epoll_table[] = { > > }; > > #endif /* CONFIG_SYSCTL */ > > > > +static atomic_t wakesource_create_id = ATOMIC_INIT(0); > > static const struct file_operations eventpoll_fops; > > > > static inline int is_file_epoll(struct file *f) > > @@ -1451,15 +1452,20 @@ static int ep_create_wakeup_source(struct epitem *epi) > > { > > struct name_snapshot n; > > struct wakeup_source *ws; > > + pid_t task_pid; > > + int id; > > + > > + task_pid = task_pid_nr(current); > > > > if (!epi->ep->ws) { > > - epi->ep->ws = wakeup_source_register(NULL, "eventpoll"); > > + epi->ep->ws = wakeup_source_register(NULL, "epoll:%d", task_pid); > > if (!epi->ep->ws) > > return -ENOMEM; > > } > > > > + id = atomic_inc_return(&wakesource_create_id); > > take_dentry_name_snapshot(&n, epi->ffd.file->f_path.dentry); > > - ws = wakeup_source_register(NULL, n.name.name); > > + ws = wakeup_source_register(NULL, "epollitem%d:%d.%s", id, task_pid, n.name.name); > > release_dentry_name_snapshot(&n); > > > > if (!ws) > > diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h > > index aa3da6611533..cb91c84f6f08 100644 > > --- a/include/linux/pm_wakeup.h > > +++ b/include/linux/pm_wakeup.h > > @@ -95,7 +95,7 @@ extern void wakeup_source_destroy(struct wakeup_source *ws); > > extern void wakeup_source_add(struct wakeup_source *ws); > > extern void wakeup_source_remove(struct wakeup_source *ws); > > extern struct wakeup_source *wakeup_source_register(struct device *dev, > > - const char *name); > > + const char *fmt, ...); > > extern void wakeup_source_unregister(struct wakeup_source *ws); > > extern int wakeup_sources_read_lock(void); > > extern void wakeup_sources_read_unlock(int idx); > > @@ -137,7 +137,7 @@ static inline void wakeup_source_add(struct wakeup_source *ws) {} > > static inline void wakeup_source_remove(struct wakeup_source *ws) {} > > > > static inline struct wakeup_source *wakeup_source_register(struct device *dev, > > - const char *name) > > + const char *fmt, ...) > > { > > return NULL; > > } > > -- > > 2.31.0.208.g409f899ff0-goog > > > > > -- > Manish Varma | Software Engineer | varmam@google.com | 650-686-0858