From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 94D5F318B83; Thu, 4 Jun 2026 07:35:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780558543; cv=none; b=qsBjHYOSWotzHH7K6/xzJU1s/8kaWjQbcJyzw/XDTk2b/5qbD8mAdaFin89hPU+iXl/rAxMTrCFUqBjGJuIhd9r51QbgCFeex7EH22zBanpb+SlbrdArm49cct3UzCF7Vr0dndVxGhDP0+sEbTaYF+vrT1EOY4IrQPwnKQLIeWA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780558543; c=relaxed/simple; bh=mirkgjfF+dpCIZzWRJzEHU3RtOI4HGEEuDGdxg/Jdfg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=e/gimcuY8TJZFaigGJ2BVrXTpebe1VbHTb4m37wV5D4aPFNK88Y24QGz1955etH49ZDXkWIWs9mXpGdbckDpMpwVy9mu7mYVgYLg0xSlT65mM/VNTuVO4rZC5XPUnBF6I+vriFzYQ8zGJR+SVBOwsztyPoR2hXw665ODfpBy+FM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jDwBqXnK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jDwBqXnK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6704A1F00893; Thu, 4 Jun 2026 07:35:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780558542; bh=tTbdFo/eiGyuAmjSs4sKcnxBavN3f7YIKZ6weBXs2/8=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=jDwBqXnKhVbnpDUK6fabMTZB0oLrH8R46x1dZH+YW9dHF0YaaQxDOmP4Vktvy3GLX do3byvDj3Qpg6mxJ+LhYcl5uSt5HR28PZv5CL7KRuIsw0tWc0yg6wY5+rHD6qhsP+r POFWnngBRtW/nP5iMbIGojzavGOtmwJxD+ylJDWzCITG7o5UQ5zbFJm5hjZ+UfGsC3 R+AR6WVYtQOtNIU+crVHPpUUDrBBnZP0n1D7qab63UjG0S63idM7lyWW/itp6z+LVD fNcm7RpMLx8d3x/hkJZf+cjb35ywj3QwRr6tmqoAkjf/WaIz8BIvzuOqklV92M6MK4 G/UGnMh2UocKg== Message-ID: <29bd5886-15c7-462b-8a39-f2ff25269ddf@kernel.org> Date: Thu, 4 Jun 2026 09:35:36 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/slab: improve kmem_cache_alloc_bulk Content-Language: en-US To: Harry Yoo , rob.clark@oss.qualcomm.com Cc: Christoph Hellwig , Andrew Morton , Mark Brown , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Jesper Dangaard Brouer , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, io-uring@vger.kernel.org, kasan-dev@googlegroups.com, bpf@vger.kernel.org, netdev@vger.kernel.org, Alexander Lobakin , Boris Brezillon References: <20260528093437.2519248-1-hch@lst.de> <20260528093437.2519248-2-hch@lst.de> <5f7f90d8-cb32-4ffb-8f1c-0722aafbe869@kernel.org> <20260529135045.GA10647@lst.de> <5f3ba603-a6ad-4cf2-9a54-aebc10273c59@kernel.org> <58cc76e7-2348-443d-a989-2a06e61178af@kernel.org> <20260601113831.GA25535@lst.de> <5e6948b3-d235-4b61-aed7-e8b4d0f5b452@kernel.org> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/4/26 09:10, Harry Yoo wrote: > > > On 6/4/26 1:22 AM, Vlastimil Babka (SUSE) wrote: >> On 6/3/26 13:13, Rob Clark wrote: >>> On Wed, Jun 3, 2026 at 2:17 AM Vlastimil Babka (SUSE) wrote: >>>> >>>> We know p->pages is NULL in this case, right? Because it was allocated by >>>> vm_bind_job_create() using kzalloc(). >>>> And the job can't be reused with a leftover value? >>>> (msm_iommu_pagetable_prealloc_cleanup doesn't set p->pages to zero). >>>> Or should we set p->pages to NULL here. >>> >>> Correct, the job is not reused. But I suppose setting p->pages to >>> NULL would make things more obvious, so no objection to that. >> >> OK, did that, just in case. Thanks. > > The kvfree() -> kfree() part should probably be a separate patch > with Fixes: 830d68f2cb8a ("drm/msm: Fix pgtable prealloc error > path") and Cc: stable? > > ...as the commit landed v6.18. Hm right, but realistically, can there be so many pages necessary, that the array to hold their pointers would be over what kmalloc() can provide? >>> BR, >>> -R >>> >>>>> + >>>>> p->pages = kvmalloc_objs(*p->pages, p->count); >>>>> if (!p->pages) >>>>> return -ENOMEM; >>>>> >>>>> ret = kmem_cache_alloc_bulk(pt_cache, GFP_KERNEL, p->count, p->pages); >>>>> if (ret != p->count) { >>>>> - kfree(p->pages); >>>>> + kvfree(p->pages); >>>>> p->pages = NULL; >>>>> p->count = ret; >>>>> return -ENOMEM; >