From: Eric Dumazet <edumazet@google.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Christoph Hellwig <hch@lst.de>, Joerg Roedel <jroedel@suse.de>,
iommu@lists.linux-foundation.org,
Eric Dumazet <eric.dumazet@gmail.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] dma-debug: dynamic allocation of hash table
Date: Fri, 31 Jan 2020 06:42:28 -0800 [thread overview]
Message-ID: <CANn89iKfA+yPHiL4R7-jkewwhDgM6jkwhW5o9H=VL9CnyBikhw@mail.gmail.com> (raw)
In-Reply-To: <f870ae85-995f-7866-ebbd-95b89ca28dc5@arm.com>
On Fri, Jan 31, 2020 at 4:30 AM Robin Murphy <robin.murphy@arm.com> wrote:
>
> ...and when that represents ~5% of the total system RAM it is a *lot*
> less reasonable than even 12KB. As I said, it's great to make a debug
> option more efficient such that what it observes is more representative
> of the non-debug behaviour, but it mustn't come at the cost of making
> the entire option unworkable for other users.
>
Then I suggest you send a patch to reduce PREALLOC_DMA_DEBUG_ENTRIES
because having 65536 preallocated entries consume 4 MB of memory.
Actually this whole attempt to re-implement slab allocations in this
file is suspect.
Do not get me wrong, but if you really want to run linux on a 16MB host,
I guess you need to add CONFIG_BASE_SMALL all over the places,
not only in this kernel/dma/debug.c file.
next prev parent reply other threads:[~2020-01-31 14:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-30 19:10 [PATCH] dma-debug: dynamic allocation of hash table Eric Dumazet
2020-01-30 23:46 ` Robin Murphy
2020-01-31 0:17 ` Eric Dumazet
2020-01-31 12:30 ` Robin Murphy
2020-01-31 14:42 ` Eric Dumazet [this message]
2020-01-31 17:43 ` Robin Murphy
2020-01-31 17:46 ` Eric Dumazet
2020-02-01 0:06 ` Robin Murphy
2020-01-31 9:06 ` Geert Uytterhoeven
2020-01-31 11:33 ` Robin Murphy
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