From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: hch@lst.de, m.szyprowski@samsung.com,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
cai@gmx.us, salil.mehta@huawei.com, john.garry@huawei.com
Subject: Re: [PATCH 3/4] dma-debug: Dynamically expand the dma_debug_entry pool
Date: Tue, 4 Dec 2018 15:29:38 +0100 [thread overview]
Message-ID: <20181204142938.GC2767@lst.de> (raw)
In-Reply-To: <f99ea022be92a99339404867bc925f4fbd2ee6c4.1543856576.git.robin.murphy@arm.com>
> + for (retry_count = 0; ; retry_count++) {
> + spin_lock_irqsave(&free_entries_lock, flags);
> +
> + if (num_free_entries > 0)
> + break;
>
> spin_unlock_irqrestore(&free_entries_lock, flags);
Taking a spinlock just to read a single integer value doesn't really
help anything.
> +
> + if (retry_count < DMA_DEBUG_DYNAMIC_RETRIES &&
> + !prealloc_memory(DMA_DEBUG_DYNAMIC_ENTRIES))
Don't we need GFP_ATOMIC here? Also why do we need the retries?
next prev parent reply other threads:[~2018-12-04 14:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 17:28 [PATCH 0/4] dma-debug: implement dynamic entry allocation Robin Murphy
2018-12-03 17:28 ` [PATCH 1/4] dma-debug: Use pr_fmt() Robin Murphy
2018-12-04 14:26 ` Christoph Hellwig
2018-12-04 17:35 ` Joe Perches
2018-12-03 17:28 ` [PATCH 2/4] dma-debug: Refactor dma_debug_entry allocation Robin Murphy
2018-12-04 14:27 ` Christoph Hellwig
2018-12-04 16:09 ` Robin Murphy
2018-12-03 17:28 ` [PATCH 3/4] dma-debug: Dynamically expand the dma_debug_entry pool Robin Murphy
2018-12-03 18:23 ` John Garry
2018-12-04 13:11 ` Robin Murphy
2018-12-04 14:17 ` Christoph Hellwig
2018-12-04 16:06 ` Robin Murphy
2018-12-04 16:30 ` John Garry
2018-12-04 17:19 ` Robin Murphy
2018-12-04 17:38 ` John Garry
2018-12-04 14:29 ` Christoph Hellwig [this message]
2018-12-04 16:32 ` Robin Murphy
2018-12-03 17:28 ` [RFC 4/4] dma-debug: Make leak-like behaviour apparent Robin Murphy
2018-12-04 14:31 ` Christoph Hellwig
2018-12-03 17:34 ` [PATCH 0/4] dma-debug: implement dynamic entry allocation Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181204142938.GC2767@lst.de \
--to=hch@lst.de \
--cc=cai@gmx.us \
--cc=iommu@lists.linux-foundation.org \
--cc=john.garry@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=robin.murphy@arm.com \
--cc=salil.mehta@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox