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Date:   Sun, 19 May 2019 22:56:57 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Jaewon Kim <jaewon31.kim@gmail.com>
Cc:     gregkh@linuxfoundation.org, m.szyprowski@samsung.com,
        linux-mm@kvack.org, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Jaewon Kim <jaewon31.kim@samsung.com>, ytk.lee@samsung.com
Subject: Re: [RFC PATCH] usb: host: xhci: allow __GFP_FS in dma allocation
Message-ID: <20190520055657.GA31866@infradead.org>
References: <CAJrd-UuMRdWHky4gkmiR0QYozfXW0O35Ohv6mJPFx2TLa8hRKg@mail.gmail.com>
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Folks, you can't just pass arbitary GFP_ flags to dma allocation
routines, beause very often they are not just wrappers around
the page allocator.

So no, you can't just fine grained control the flags, but the
existing code is just as buggy.

Please switch to use memalloc_noio_save() instead.