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 088B1C77B7F for ; Sat, 13 May 2023 19:42:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229624AbjEMTm4 (ORCPT ); Sat, 13 May 2023 15:42:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbjEMTmx (ORCPT ); Sat, 13 May 2023 15:42:53 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DEBD1BC7 for ; Sat, 13 May 2023 12:42:53 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1684006971; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=xhIUhkm/3QxY0cQ35omU8A+ztIuN9wN4GJw2r9D9N8c=; b=4j5yDWsZaysSy25nQ55wrWrPJWnm9WFsLnteMJ92iU+X5vqMz9/sgIOgPPvscoCmFxAPlT xGfKRi0hHldOz9J/TvQaTfle2Bv5h8nra2WAiAi3BtCuT9nHAt1DRCXaV6ZNoSiwKNplq2 b/SJXx4cpr4wgmI8ESC0x/5uCwASHEvIdILO6MKFEeLy1YZY1KD3gs5z0cxENJDCzLNZzu FxRCtgCg9stdEZdWfd2F8PUJMl+V0LPdJeW03wq8+oPqzHdmeHIccIhUMjU2sPY0LkJqJH cOnKrhRXBCXB8IMhJNoIkm654+v3PSaqPeCOW5g/a5aMBNgKWi9OELsi6P+t/w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1684006971; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=xhIUhkm/3QxY0cQ35omU8A+ztIuN9wN4GJw2r9D9N8c=; b=FuUB6NJJ8piz48iH2rmyp4RMcQPrmrPihGRisRlSDu9P0zpwEuq2dlrdvoje3pqAVOz17d 9Exm3eB02HcJtSAA== To: Tetsuo Handa , Andrew Morton Cc: syzbot , syzkaller-bugs@googlegroups.com, Ingo Molnar , linux-kernel@vger.kernel.org, linux-mm , Peter Zijlstra Subject: Re: [PATCH] debugobject: don't wake up kswapd from fill_pool() In-Reply-To: References: <000000000000008ddb05fb5e2576@google.com> <6577e1fa-b6ee-f2be-2414-a2b51b1c5e30@I-love.SAKURA.ne.jp> <20230511204458.819f9009d2ef8b46cc163191@linux-foundation.org> <87v8gxbthf.ffs@tglx> <39c79d27-73ea-06a8-62fe-2b64d0fd8db5@I-love.SAKURA.ne.jp> <87bkipbeyr.ffs@tglx> <61d7ac52-3352-b7cd-8908-890a29a007d9@I-love.SAKURA.ne.jp> <87lehsaavo.ffs@tglx> Date: Sat, 13 May 2023 21:42:51 +0200 Message-ID: <87fs809fwk.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 13 2023 at 18:33, Tetsuo Handa wrote: > On 2023/05/13 17:33, Thomas Gleixner wrote: >> Now I just stared at __alloc_pages_slowpath() and looked at the >> condition for wakeup_all_kswapds(). ALLOC_KSWAPD is set because >> debugobject uses GFP_ATOMIC which contains __GFP_KSWAPD_RECLAIM. >> >> So debug objects needs to have s/GFP_ATOMIC/__GFP_HIGH/ to prevent that >> wakeup path. > > Yes. That is exactly what my patch does. Indeed. For some reason your patch (though you cc'ed me) did not show up in my inbox. I've grabbed it from lore so no need to resend. Actually we want both changes. - Your's to fix the underlying ancient problem. - The one I did which restores the performance behaviour Thanks, tglx