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 4C2923EAC62 for ; Tue, 10 Mar 2026 20:29:08 +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=1773174548; cv=none; b=I9xUqaM4k8qBfeWPP8En5aQOc4vPIp5NZW/y0uq/G77jSqtUM0J3cMW9NY5AhMfpdvJKZk9xpfL7Esy/FbbJt7l9DVFQtKt4PLRKBoqbvt5z3+RrEifeFOlyILuvX8Rx4BKflJkh8KehpkHr+M7aeDFEbTp5rspDI+d8uL6/B3w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773174548; c=relaxed/simple; bh=eRWJmG0Xt0fYDFAd6Vd/md9H9N9F8Ozc6BTWFL8Y9CM=; h=Date:Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=D5htQWCk0nO0lBGlpJqbLqF9bn9PeWtSJz/yvUhxcZyVHxnoIifwDYMlnKouRNS7IqVI4BuyrP7nUfjK3EaaZZR+yIBBzOhPgjWIaB1Xmi9FnAE6wb/OX+rQchSDwYoCHh99uNjvmVfvLW8VV/cOnTh8odNfQNH0KjFX0GMw024= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vsu8zqw6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vsu8zqw6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3EA67C2BC87; Tue, 10 Mar 2026 20:29:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773174547; bh=eRWJmG0Xt0fYDFAd6Vd/md9H9N9F8Ozc6BTWFL8Y9CM=; h=Date:From:To:Cc:Subject:References:From; b=Vsu8zqw67dDv/K/Am01VHC3+wVa1GxqkezjgHtYMaaz4s6231myNYY+kc5yu5+c+4 gWy/krmQLcUqe9YbCJyIzsAWYvDGHfvtF4zh/WTScH7tPNfvUH4IOHijg0vSlDB+2v bGu8ShRvxdzFEtx6AszC2lKOoJIiR2WCgdCkW96pVZXqHdFde3ujHDk5DFdV5ACZt6 tcJc/EWOnV6o7xyjjPyN+qQqB7cJsxv/bpfJG7Q594QmCwtfx6COOk0pmYDKMI2Ti6 iRxkCPOwqB1+5tzhp6rlR16ABAUrScEXW/2Wvlrq9zNv8KSwa7alKV8TYxgOmkuc2P pYmP+bM40Xi1A== Date: Tue, 10 Mar 2026 21:29:04 +0100 Message-ID: <20260310202526.116363613@kernel.org> User-Agent: quilt/0.68 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Mathieu Desnoyers , Matthieu Baerts , Jiri Slaby Subject: [patch 3/4] sched/mmcid: Remove pointless preempt guard References: <20260310201009.257617049@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 This is a leftover from the early versions of this function where it could be invoked without mm::mm_cid::lock held. Remove it and add lockdep asserts instead. Fixes: 653fda7ae73d ("sched/mmcid: Switch over to the new mechanism") Signed-off-by: Thomas Gleixner --- kernel/sched/core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10685,6 +10685,8 @@ static void mm_cid_fixup_tasks_to_cpus(v static bool sched_mm_cid_add_user(struct task_struct *t, struct mm_struct *mm) { + lockdep_assert_held(&mm->mm_cid.lock); + t->mm_cid.active = 1; mm->mm_cid.users++; return mm_update_max_cids(mm); @@ -10737,12 +10739,12 @@ static void sched_mm_cid_fork(struct tas static bool sched_mm_cid_remove_user(struct task_struct *t) { + lockdep_assert_held(&t->mm->mm_cid.lock); + t->mm_cid.active = 0; - scoped_guard(preempt) { - /* Clear the transition bit */ - t->mm_cid.cid = cid_from_transit_cid(t->mm_cid.cid); - mm_unset_cid_on_task(t); - } + /* Clear the transition bit */ + t->mm_cid.cid = cid_from_transit_cid(t->mm_cid.cid); + mm_unset_cid_on_task(t); t->mm->mm_cid.users--; return mm_update_max_cids(t->mm); }