From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 2DF3B349B1F for ; Thu, 19 Feb 2026 17:10:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771521047; cv=none; b=dWs/3QB/fmreSdDngm3tgBUJ1jfTqWdYztBG6fG6H9xK7ILp5HgZtioj0OTH1oCRopZc7z6Gm/SnaFf9/03S7sfjM4NiSAz0s2VdRkkwzHMAqykYge8vgr9WIY7UzfL/IO7kaoGGa9/ekYayw4OHdLEqk9zrEsbqe4M1VnxCNvM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771521047; c=relaxed/simple; bh=QbyQavlhyozMCjXnRyzWHvLmvlB3aLyQrMvP1c9kYNA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JdDqCeoexybeT7mhAgWIszTjE+C1dh3hYpVqbP13nuC9GxkbuH1phRk+v2/MV+A1wKIP3ZhktSCBW2r3HZUTMz9ZcW97PZYG0LWSxmOY282kuihMVO86HluhTlmUKlJAxDqhN08sdSWmtGweLO1xWe7zzkhvVo9UzTaB/1QO8Vg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YD3SyL0D; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=W7rMfmYM; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YD3SyL0D"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="W7rMfmYM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1771521045; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1ufSHZcVh+Dpk6NOIfY9tkcU2Fx29sq1FQcHOa9iMf4=; b=YD3SyL0DtxRA91L5WAKXCYQ49f11bVorKkKPHTjx76X12k2V8XY093Hmdx/kmeAwV2kQIB c/Jfb1c0SKNR5acXyF7CZzISngRFYbe3wTfO3a6i8FAYN2X7mJaAMT9CCqjvcbIjPjedn2 91+ainb9FsRHvogQ74qW1FkNQuY+aoU= Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-116-95W-Eau4PouPeQEuByTNTA-1; Thu, 19 Feb 2026 12:10:43 -0500 X-MC-Unique: 95W-Eau4PouPeQEuByTNTA-1 X-Mimecast-MFC-AGG-ID: 95W-Eau4PouPeQEuByTNTA_1771521043 Received: by mail-qk1-f198.google.com with SMTP id af79cd13be357-8c71655aa11so1166426085a.3 for ; Thu, 19 Feb 2026 09:10:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1771521043; x=1772125843; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=1ufSHZcVh+Dpk6NOIfY9tkcU2Fx29sq1FQcHOa9iMf4=; b=W7rMfmYMUAHGzUpxb1gboGht0D4GtVfcu6E69+I2FsjJE8m+kkuTfjvTJ6zvtYCtYS 7qp2hwDxWL4ZoCUzfzA+0pmRHsyxHzfYzT20wFMGKZiRUL+leKprsRjU8OAqdrtv1iWw AlGc0Rb9/rU8hzgcABTCCEZ9WXq0cef/cTQQjwujtyEB9cZu+mm7hrFS5CJAP+FHoRQ/ v8OgWm7pInylgZQaRY8VtIVbBBKByjAT5CRlmyCwQDccRX0ma6lCSmVuFSk6uGsBjJ9y cXSlrIdtp0tDenvh7aBR0cplvxrgfuHM6XNgabq/1Iks2f1RjI5reiFqK+YXHYP4Ztmv J2Fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771521043; x=1772125843; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1ufSHZcVh+Dpk6NOIfY9tkcU2Fx29sq1FQcHOa9iMf4=; b=UvMeROBRm1mgqQymKNMwlDHy8nvaYCkQKxFQGrFaBE36zWD/SLIgAI/mr4s/7jy+Tz o0ld3/pbtxzDjD6ktawUiMs1jmDV7AQUQs/e7oj/yg7WrP6EpzDIR9idXbchxIQOP63l Am3OrX8ZZU6UjCbt0kFXm1obpwLwoDQd4yGEMsCuNs0MKe+pfKVybAhTOXosqN6iCNC7 fWciuHS0ry/YBqhbgBgHUINNWpmNXKCh82SiC8D34Yt5+jmOJMejj0XNfsYU1tOJWSEr hh9ha/X6SjShdGEkBSSFU9UmUdqiBxG5E7G58I7tBJrVJ7jE1C78HrT/c08TTbQofdwH PbPg== X-Forwarded-Encrypted: i=1; AJvYcCVcl7Ky3a2QGMW1xkrrqAXZ46IiSGRl8J1Wa6326v3JRv0bshek76ETOFVle+FWGCAB3x7Jsq6W2ms5/bU=@vger.kernel.org X-Gm-Message-State: AOJu0Yxbg5k8XMZ45zkGJSEg0gMym0ciLtoWK45NQ0SKC+eLkvkb0+LG +gOgqjF84DwQkbuwvhF7hHqe9KhMGvTNG2/euaQnM5tlMeRLDCwyrXpH55kBNl+Ffw+Pj0Ft7iQ CWqupMeO/5tCvuoh095RTGZJsl2b+5ChlBzIl+9d5GuhO04Xo2wZJ3AyUig8bsD+QTg== X-Gm-Gg: AZuq6aLxCmxe8qKfQjDR5nYtGnVkKHCG4ilHYOlKPfz7LsFkpLoWynEfEAtqC7NpE4H TDXk/KuiBZT+yOx28CjvGtYTMPpg0sPrTLsPGKUtQ4j7aj5MfZDoZrer8KOYn4bj752NsHGib/Z S6Nh/+lOjOy7S619t/BCKq/y75Y973e3DipmUZyl0iVpI6D7n/R5YBsEWfJpvkPTgAQqkzCIS8r X5Og0nT9OYR8/toqkkyFJeuTFfYSdGm7iFePFHTpzWtFpv0tWOXO96Y4Y9Vi2cj+Df7A479CBH7 N5d93m70+7B3LDULbmhWcoB8Z+DtOhIFkeVEaA6PZ/3jUr97R81H9o8Jz89HA/Rg7LbwvMSBKdV MoAvqc/5mJi+FnD7IKUY8d5FfCFvLbE1xiDuJ5/Je01g/mclWb8bqspMtwf2aRRI= X-Received: by 2002:a05:620a:44c2:b0:8c7:fdc:e877 with SMTP id af79cd13be357-8cb740b5c53mr703611785a.41.1771521043254; Thu, 19 Feb 2026 09:10:43 -0800 (PST) X-Received: by 2002:a05:620a:44c2:b0:8c7:fdc:e877 with SMTP id af79cd13be357-8cb740b5c53mr703604885a.41.1771521042525; Thu, 19 Feb 2026 09:10:42 -0800 (PST) Received: from localhost (pool-100-17-19-56.bstnma.fios.verizon.net. [100.17.19.56]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8cb2b0e12eesm2128955585a.15.2026.02.19.09.10.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Feb 2026 09:10:42 -0800 (PST) Date: Thu, 19 Feb 2026 12:10:41 -0500 From: Eric Chanudet To: Christian =?utf-8?B?S8O2bmln?= Cc: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, Maxime Ripard , Albert Esteve , linux-mm@kvack.org Subject: Re: [PATCH v2 3/3] dma-buf: heaps: cma: charge each cma heap's dmem Message-ID: References: <20260218-dmabuf-heap-cma-dmem-v2-0-b249886fb7b2@redhat.com> <20260218-dmabuf-heap-cma-dmem-v2-3-b249886fb7b2@redhat.com> <435330fd-ecdd-43c7-8527-f285c03c6421@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <435330fd-ecdd-43c7-8527-f285c03c6421@amd.com> On Thu, Feb 19, 2026 at 08:17:28AM +0100, Christian König wrote: > > > On 2/18/26 18:14, Eric Chanudet wrote: > > The cma dma-buf heaps let userspace allocate buffers in CMA regions > > without enforcing limits. Since each cma region registers in dmem, > > charge against it when allocating a buffer in a cma heap. > > > > Signed-off-by: Eric Chanudet > > --- > > drivers/dma-buf/heaps/cma_heap.c | 15 ++++++++++++++- > > 1 file changed, 14 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c > > index 49cc45fb42dd7200c3c14384bcfdbe85323454b1..bbd4f9495808da19256d97bd6a4dca3e1b0a30a0 100644 > > --- a/drivers/dma-buf/heaps/cma_heap.c > > +++ b/drivers/dma-buf/heaps/cma_heap.c > > @@ -27,6 +27,7 @@ > > #include > > #include > > #include > > +#include > > > > #define DEFAULT_CMA_NAME "default_cma_region" > > > > @@ -58,6 +59,7 @@ struct cma_heap_buffer { > > pgoff_t pagecount; > > int vmap_cnt; > > void *vaddr; > > + struct dmem_cgroup_pool_state *pool; > > }; > > > > struct dma_heap_attachment { > > @@ -276,6 +278,7 @@ static void cma_heap_dma_buf_release(struct dma_buf *dmabuf) > > kfree(buffer->pages); > > /* release memory */ > > cma_release(cma_heap->cma, buffer->cma_pages, buffer->pagecount); > > + dmem_cgroup_uncharge(buffer->pool, buffer->len); > > kfree(buffer); > > } > > > > @@ -319,9 +322,17 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap, > > if (align > CONFIG_CMA_ALIGNMENT) > > align = CONFIG_CMA_ALIGNMENT; > > > > + if (mem_accounting) { > > Since mem_accounting is a module parameter it is possible to make it changeable during runtime. > > IIRC it currently is read only, but maybe add a one line comment that the cma heap now depends on that. > Agreed, while read-only it is easily missed without at least a comment. Alternatively, should that value be captured in the init callback to guaranty it is set once and make this requirement clearer? Thanks, > Apart from that the series looks totally sane to me. > > Regards, > Christian. > > > + ret = dmem_cgroup_try_charge( > > + cma_get_dmem_cgroup_region(cma_heap->cma), size, > > + &buffer->pool, NULL); > > + if (ret) > > + goto free_buffer; > > + } > > + > > cma_pages = cma_alloc(cma_heap->cma, pagecount, align, false); > > if (!cma_pages) > > - goto free_buffer; > > + goto uncharge_cgroup; > > > > /* Clear the cma pages */ > > if (PageHighMem(cma_pages)) { > > @@ -376,6 +387,8 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap, > > kfree(buffer->pages); > > free_cma: > > cma_release(cma_heap->cma, cma_pages, pagecount); > > +uncharge_cgroup: > > + dmem_cgroup_uncharge(buffer->pool, size); > > free_buffer: > > kfree(buffer); > > > > > -- Eric Chanudet