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 704F1C7EE22 for ; Thu, 11 May 2023 07:57:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237431AbjEKH5C (ORCPT ); Thu, 11 May 2023 03:57:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231625AbjEKH46 (ORCPT ); Thu, 11 May 2023 03:56:58 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1BB6269E for ; Thu, 11 May 2023 00:56:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+CGH7YHU79D1x2zo+JX/L+1Yeo4Kpnw8RAg9mt4T5fI=; b=JaYNfxN6UpDjkg5TCFsg9BwlN+ c3txs50rIc3hX+JmCPER1Hf2OJ0PvJ42OxnSzvJ0Vbi2Mta7+67wKYBtcaDiQmphbwPBIJ3GZEr5m zZlA0Sy/tUFu4dFj327ul1jgXZhqfOJ2HcaSXe2NzKlloGT5etzz4BaWeV4u7zZHeFe+BOhyCIZZV DBHeUz2iirtSu7ToxV5lgyWz+5QtGJJ7fd7I9qmEtdvZWpKosNwMZQ/VuhYRBPBfji7KY+5vSBLs3 TpPTaXhpTweZBq8I+hJKrv3Yh/wC7S5t59n+xdZScabJ9jlSJ0DBAjL0YpZJp9FuQKLJswTHJ+uzG AXpqQ42A==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1px1AA-008AyE-2u; Thu, 11 May 2023 07:56:35 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B7948300023; Thu, 11 May 2023 09:56:32 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5D70C235CC442; Thu, 11 May 2023 09:56:32 +0200 (CEST) Date: Thu, 11 May 2023 09:56:32 +0200 From: Peter Zijlstra To: Pavel Tikhomirov Cc: Thomas Gleixner , Frederic Weisbecker , LKML , Anna-Maria Behnsen , syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com, Dmitry Vyukov , Sebastian Siewior , Michael Kerrisk , Andrei Vagin , Christian Brauner , Alexander Mikhalitsyn , Pavel Emelyanov Subject: Re: [RFD] posix-timers: CRIU woes Message-ID: <20230511075632.GR4253@hirez.programming.kicks-ass.net> References: <87zg6i2xn3.ffs@tglx> <87v8h62vwp.ffs@tglx> <878rdy32ri.ffs@tglx> <87v8h126p2.ffs@tglx> <875y911xeg.ffs@tglx> <87ednpyyeo.ffs@tglx> <009e7658-1377-cc79-7a42-4dda8fec5af0@virtuozzo.com> <87wn1gy4e6.ffs@tglx> <005a944c-ed2e-6010-a534-26d5947402da@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <005a944c-ed2e-6010-a534-26d5947402da@virtuozzo.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 11, 2023 at 12:12:32PM +0800, Pavel Tikhomirov wrote: > Not sure how kernel memory consumption increases with sparse timer IDs, > global hashtable (posix_timers_hashtable) is the same size anyway, entries > in hlists can be distributed differently as hash depends on id directly but > we have same number of entries. Probably I miss something, why do we need > dense IDs? The proposal was to remove the global hash and use a signal_struct based xarray instead.