Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261670AbVAISQt (ORCPT ); Sun, 9 Jan 2005 13:16:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261663AbVAISQs (ORCPT ); Sun, 9 Jan 2005 13:16:48 -0500 Received: from [213.85.13.118] ([213.85.13.118]:17537 "EHLO tau.rusteko.ru") by vger.kernel.org with ESMTP id S261670AbVAISQl (ORCPT ); Sun, 9 Jan 2005 13:16:41 -0500 To: Marcelo Tosatti Cc: Andrew Morton , pmarques@grupopie.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, hch@infradead.org Subject: Re: [RFC] per thread page reservation patch References: <1105019521.7074.79.camel@tribesman.namesys.com> <20050107144644.GA9606@infradead.org> <1105118217.3616.171.camel@tribesman.namesys.com> <41DEDF87.8080809@grupopie.com> <20050107132459.033adc9f.akpm@osdl.org> <20050107150315.3c1714a4.akpm@osdl.org> <20050107154305.790b8a51.akpm@osdl.org> <20050109113551.GB9144@logos.cnet> From: Nikita Danilov Date: Sun, 09 Jan 2005 21:16:24 +0300 In-Reply-To: <20050109113551.GB9144@logos.cnet> (Marcelo Tosatti's message of "Sun, 9 Jan 2005 09:35:51 -0200") Message-ID: User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.5 (chayote, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1283 Lines: 31 Marcelo Tosatti writes: [...] > > - all instances of an allocator from the current thread will eat from the perthread > reserves, you probably want only a few special allocations to eat from the reserves? > Thing is its not really a reservation intended for emergency situations, > rather a "generic per-thread pool" the way things are now. Per-thread reservations are only useful when they are transparent. If users have to call special function, or to pass special flag to __alloc_pages() they might just use mempool as well. Idea is to reserve some number of pages before starting complex operation so that generic function (like find_get_page()) called as part of this operation are guaranteed to succeed. > > - its a real fast path, we're adding quite some instructions there which are only > used by reiserfs now. Yes, this worries me too. Possibly we should move this check below in __alloc_pages(), so that per-thread reservation is only checked if fast-path allocation failed. Nikita. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/