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 0365EC4167B for ; Thu, 2 Nov 2023 12:32:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347360AbjKBMcY (ORCPT ); Thu, 2 Nov 2023 08:32:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345993AbjKBMcX (ORCPT ); Thu, 2 Nov 2023 08:32:23 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09C56112 for ; Thu, 2 Nov 2023 05:32:21 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12BF9C433C7; Thu, 2 Nov 2023 12:32:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698928340; bh=DkUXd46otsJWfRY3oEiVnOzehyH5Ghvb1Jd4QF6lQEc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Iqwwr413V+akq7R3afJNaobAFRXuIhlHj6oR4b6iuooDovhIqlfTArarD26ff33uP VSe3qqP403J74iHnJIGWkALsyTfylqUCiIF1OhIHSp+xc/w/Mg/QQ/tCcR9XZqCpG4 EKbjxpAF+bLZDro0hFkVLeuS0+3jistIO//l5vnek5fLeqB5yEsxp9Mk7kF86V6aKX tMEMxz/+usYhYVTWBG5jTaefQ4incED0C5uXvwYbKsyTJRtFxSLX3c226Kx3/SDkO7 bvL+gTXD26/g/w8E28rNJMZ/gQ9guxTc/qhclJSSd0AnKxLAawMCxu/m+MtTt0gpuX 9WzyE/2GgNh4A== Date: Thu, 2 Nov 2023 14:32:16 +0200 From: Leon Romanovsky To: Maxim Samoylov , Bernard Metzler , Dennis Dalessandro Cc: Guoqing Jiang , "linux-rdma@vger.kernel.org" , Jason Gunthorpe , Christian Benvenuti , Vadim Fedorenko Subject: Re: [PATCH v2] IB: rework memlock limit handling code Message-ID: <20231102123216.GF5885@unreal> References: <20231012082921.546114-1-max7255@meta.com> <20231015091959.GC25776@unreal> <5fcf502d-71fb-123d-f6ff-f3ffb7c3ba1a@linux.dev> <20231023055229.GB10551@unreal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Tue, Oct 31, 2023 at 01:30:27PM +0000, Maxim Samoylov wrote: > On 23/10/2023 07:52, Leon Romanovsky wrote: > > On Mon, Oct 23, 2023 at 09:40:16AM +0800, Guoqing Jiang wrote: > >> > >> > >> On 10/15/23 17:19, Leon Romanovsky wrote: > >>> On Thu, Oct 12, 2023 at 01:29:21AM -0700, Maxim Samoylov wrote: > >>>> This patch provides the uniform handling for RLIM_INFINITY value > >>>> across the infiniband/rdma subsystem. > >>>> > >>>> Currently in some cases the infinity constant is treated > >>>> as an actual limit value, which could be misleading. > >>>> > >>>> Let's also provide the single helper to check against process > >>>> MEMLOCK limit while registering user memory region mappings. > >>>> > >>>> Signed-off-by: Maxim Samoylov > >>>> --- > >>>> > >>>> v1 -> v2: rewritten commit message, rebased on recent upstream > >>>> > >>>> drivers/infiniband/core/umem.c | 7 ++----- > >>>> drivers/infiniband/hw/qib/qib_user_pages.c | 7 +++---- > >>>> drivers/infiniband/hw/usnic/usnic_uiom.c | 6 ++---- > >>>> drivers/infiniband/sw/siw/siw_mem.c | 6 +++--- > >>>> drivers/infiniband/sw/siw/siw_verbs.c | 23 ++++++++++------------ > >>>> include/rdma/ib_umem.h | 11 +++++++++++ > >>>> 6 files changed, 31 insertions(+), 29 deletions(-) > >>> <...> > >>> > >>>> @@ -1321,8 +1322,8 @@ struct ib_mr *siw_reg_user_mr(struct ib_pd *pd, u64 start, u64 len, > >>>> struct siw_umem *umem = NULL; > >>>> struct siw_ureq_reg_mr ureq; > >>>> struct siw_device *sdev = to_siw_dev(pd->device); > >>>> - > >>>> - unsigned long mem_limit = rlimit(RLIMIT_MEMLOCK); > >>>> + unsigned long num_pages = > >>>> + (PAGE_ALIGN(len + (start & ~PAGE_MASK))) >> PAGE_SHIFT; > >>>> int rv; > >>>> siw_dbg_pd(pd, "start: 0x%pK, va: 0x%pK, len: %llu\n", > >>>> @@ -1338,19 +1339,15 @@ struct ib_mr *siw_reg_user_mr(struct ib_pd *pd, u64 start, u64 len, > >>>> rv = -EINVAL; > >>>> goto err_out; > >>>> } > >>>> - if (mem_limit != RLIM_INFINITY) { > >>>> - unsigned long num_pages = > >>>> - (PAGE_ALIGN(len + (start & ~PAGE_MASK))) >> PAGE_SHIFT; > >>>> - mem_limit >>= PAGE_SHIFT; > >>>> - if (num_pages > mem_limit - current->mm->locked_vm) { > >>>> - siw_dbg_pd(pd, "pages req %lu, max %lu, lock %lu\n", > >>>> - num_pages, mem_limit, > >>>> - current->mm->locked_vm); > >>>> - rv = -ENOMEM; > >>>> - goto err_out; > >>>> - } > >>>> + if (!ib_umem_check_rlimit_memlock(num_pages + current->mm->locked_vm)) { > >>>> + siw_dbg_pd(pd, "pages req %lu, max %lu, lock %lu\n", > >>>> + num_pages, rlimit(RLIMIT_MEMLOCK), > >>>> + current->mm->locked_vm); > >>>> + rv = -ENOMEM; > >>>> + goto err_out; > >>>> } > >>> Sorry for late response, but why does this hunk exist in first place? > >>> > > Trailing newline, will definitely drop it. > > >>>> + > >>>> umem = siw_umem_get(start, len, ib_access_writable(rights)); > >>> This should be ib_umem_get(). > >> > >> IMO, it deserves a separate patch, and replace siw_umem_get with ib_umem_get > >> is not straightforward given siw_mem has two types of memory (pbl and umem). > > > > The thing is that once you convince yourself that SIW should use ib_umem_get(), > > the same question will arise for other parts of this patch where > > ib_umem_check_rlimit_memlock() is used. > > > > And if we eliminate them all, there won't be a need for this new API call at all. > > > > Thanks > > > > Hi! > > So, as for 31.10.2023 I still see siw_umem_get() call used in > linux-rdma repo in "for-next" branch. I hoped to hear some feedback from Bernard and Dennis. > > AFAIU this helper call is used only in a single place and could > potentially be replaced with ib_umem_get() as Leon suggests. > > But should we perform it right inside this memlock helper patch? > > I can submit later another patch with siw_umem_get() replaced > if necessary. > > > >> > >> Thanks, > >> Guoqing >