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 9724F1547CC for ; Thu, 17 Jul 2025 22:46:50 +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=1752792410; cv=none; b=luaIRB0A4iMoKuOjy9bnK0XdcmkLwBahrJlpHxAc1ikMjzbOlkBfCsK2Sj8m/gXzH1sOJ4pl5QYWoFmclW5V4JBeZqVkCB76iBhaIzMjztCpJKuJ2gDT6nEeWD+uA7D8335T31aqIK3OLesUnFxjpSYvdECi737EoLA7r5qbS84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752792410; c=relaxed/simple; bh=zQ1v9dEzuqEr0yx5GKfFtQl2yqF48l9ZLGZYKmcgNAw=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=dxf2SzWwp0JKV/mUOtHgiF7ONUmgAseZZO+I4ZS2QejRLVhRgOdViI8LSpmQKW2XmMu8+KMGVYI9Ooh1HgWMBBWB38kNn51ZvnmkHyKfxqJ5d6R+Zp1gBuO7YHi+zLJYXNyRrvBm00jwKCYsuntpc910uTSTw1uN6DhewRJcN7Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=OxWk/8aR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="OxWk/8aR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4679C4CEE3; Thu, 17 Jul 2025 22:46:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1752792410; bh=zQ1v9dEzuqEr0yx5GKfFtQl2yqF48l9ZLGZYKmcgNAw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OxWk/8aR8YyKI0IIfNPcT4oBKAxRHkK1+iD2RM21iDHXttBrR1xZWBs1bxljrhvOr OVQNmvsw34sGqurJl9ObDE98Dp3jHjBPbgBBKMfki9/5PmN/FqsoO6onTPSk/Y0ipq dCYGajcSSKfIKix9f5sM4Zo6YXJ+rgfcAVOrJ49I= Date: Thu, 17 Jul 2025 15:46:49 -0700 From: Andrew Morton To: Davidlohr Bueso Cc: Roman Gushchin , mhocko@kernel.org, hannes@cmpxchg.org, shakeel.butt@linux.dev, yosryahmed@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/4] mm: introduce per-node proactive reclaim interface Message-Id: <20250717154649.796cca17cf422783a79b4e5a@linux-foundation.org> In-Reply-To: <20250717162637.xz77hsj2byamivgm@offworld> References: <20250623185851.830632-1-dave@stgolabs.net> <20250623185851.830632-5-dave@stgolabs.net> <87qzyfr0u6.fsf@linux.dev> <20250717162637.xz77hsj2byamivgm@offworld> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 17 Jul 2025 09:26:37 -0700 Davidlohr Bueso wrote: > >> + if (test_and_set_bit_lock(PGDAT_RECLAIM_LOCKED, > >> + &pgdat->flags)) > >> + return -EAGAIN; > > > >Isn't EBUSY a better choice here? > >At least to distinguish between no reclaimable memory left and > >somebody else is abusing the same interface cases. > > Yes, I agree. From: Andrew Morton Subject: mm-introduce-per-node-proactive-reclaim-interface-fix Date: Thu Jul 17 03:44:14 PM PDT 2025 user_proactive_reclaim(): return -EBUSY on PGDAT_RECLAIM_LOCKED contention, per Roman Cc: Davidlohr Bueso Cc: Johannes Weiner Cc: Michal Hocko Cc: Roman Gushchin Cc: Shakeel Butt Cc: Yosry Ahmed Signed-off-by: Andrew Morton --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmscan.c~mm-introduce-per-node-proactive-reclaim-interface-fix +++ a/mm/vmscan.c @@ -7818,7 +7818,7 @@ int user_proactive_reclaim(char *buf, if (test_and_set_bit_lock(PGDAT_RECLAIM_LOCKED, &pgdat->flags)) - return -EAGAIN; + return -EBUSY; reclaimed = __node_reclaim(pgdat, gfp_mask, batch_size, &sc); _