From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6548D481AE for ; Mon, 19 Feb 2024 18:11:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708366291; cv=none; b=DL6UZnlTidgtSLshhCBCIuUYMPnasZozJ+1l9fBrwOd56V59WWnU0A6j19uGe3uke3/G3bCI+38DKR5a1PcNm6b5+KeKxdbin3PJ2sRI3EkQYP/7Gpq3aHrRUBO5W1V+CV8aY7ffFtwdhn23Hkea9++NPNmt2y/BXtyNmJAxvlM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708366291; c=relaxed/simple; bh=JXf1XRHVqmK6Wwv4Qit3WS8L0hg3IlrKQGldIMaDB90=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=cb87eGYpWYOWbnIQbkwe3Xr16ZG04ET+BwDnN7pl0BOLSjfhj7fL2icxErF8bgiOgspoUSdQ63YRgN1U9wwhb8A7+GD1eof0bZJCNjJAIZbq83mbL8AI4iOlC2BaTm1NLXHts3uz9bjzSaiVIl1xbRePLyb1PWKhJ+PEo8vRi7E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2n/o12ZF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="2n/o12ZF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C59EEC433F1; Mon, 19 Feb 2024 18:11:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708366290; bh=JXf1XRHVqmK6Wwv4Qit3WS8L0hg3IlrKQGldIMaDB90=; h=Subject:To:Cc:From:Date:From; b=2n/o12ZFPirHQycSaRLVHTgh2sROuJ6bmbvROhKETxFx11SpUj3HblUQykJQUhQ1Z GUNYsqk8y+N8bfkqVY5pMlIr8g/qIq2vtxbYBY073ijsLxwEg9/Oc26NHfSKF7pIyT 9wPepUhYZEv9Ym9wUcCazl06riCiKeivvHgAB1l8= Subject: FAILED: patch "[PATCH] getrusage: move thread_group_cputime_adjusted() outside of" failed to apply to 5.15-stable tree To: oleg@redhat.com,akpm@linux-foundation.org,dylanbhatch@google.com,ebiederm@xmission.com,stable@vger.kernel.org Cc: From: Date: Mon, 19 Feb 2024 19:11:23 +0100 Message-ID: <2024021923-promptly-dedicate-e327@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x daa694e4137571b4ebec330f9a9b4d54aa8b8089 # git commit -s git send-email --to '' --in-reply-to '2024021923-promptly-dedicate-e327@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From daa694e4137571b4ebec330f9a9b4d54aa8b8089 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Jan 2024 16:50:50 +0100 Subject: [PATCH] getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand() Patch series "getrusage: use sig->stats_lock", v2. This patch (of 2): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. This is also preparation for the next patch which changes getrusage() to use stats_lock instead of siglock, thread_group_cputime() takes the same lock. With the current implementation recursive read_seqbegin_or_lock() is fine, thread_group_cputime() can't enter the slow mode if the caller holds stats_lock, yet this looks more safe and better performance-wise. Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com Signed-off-by: Oleg Nesterov Reported-by: Dylan Hatch Tested-by: Dylan Hatch Cc: Eric W. Biederman Cc: Signed-off-by: Andrew Morton diff --git a/kernel/sys.c b/kernel/sys.c index e219fcfa112d..70ad06ad852e 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1785,17 +1785,19 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) struct task_struct *t; unsigned long flags; u64 tgutime, tgstime, utime, stime; - unsigned long maxrss = 0; + unsigned long maxrss; + struct mm_struct *mm; struct signal_struct *sig = p->signal; - memset((char *)r, 0, sizeof (*r)); + memset(r, 0, sizeof(*r)); utime = stime = 0; + maxrss = 0; if (who == RUSAGE_THREAD) { task_cputime_adjusted(current, &utime, &stime); accumulate_thread_rusage(p, r); maxrss = sig->maxrss; - goto out; + goto out_thread; } if (!lock_task_sighand(p, &flags)) @@ -1819,9 +1821,6 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) fallthrough; case RUSAGE_SELF: - thread_group_cputime_adjusted(p, &tgutime, &tgstime); - utime += tgutime; - stime += tgstime; r->ru_nvcsw += sig->nvcsw; r->ru_nivcsw += sig->nivcsw; r->ru_minflt += sig->min_flt; @@ -1839,19 +1838,24 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) } unlock_task_sighand(p, &flags); -out: + if (who == RUSAGE_CHILDREN) + goto out_children; + + thread_group_cputime_adjusted(p, &tgutime, &tgstime); + utime += tgutime; + stime += tgstime; + +out_thread: + mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + +out_children: + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ r->ru_utime = ns_to_kernel_old_timeval(utime); r->ru_stime = ns_to_kernel_old_timeval(stime); - - if (who != RUSAGE_CHILDREN) { - struct mm_struct *mm = get_task_mm(p); - - if (mm) { - setmax_mm_hiwater_rss(&maxrss, mm); - mmput(mm); - } - } - r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)