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Petersen" , linux-block@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/3] slab, block: generalize bvec_alloc_gfp Message-ID: <20251027064728.GA13145@lst.de> References: <20251023080919.9209-1-hch@lst.de> <20251023080919.9209-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Stat-Signature: jnfjuir7anangg48w4zfnuofct6jd66m X-Rspamd-Queue-Id: 51917120002 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1761547654-763241 X-HE-Meta: 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 qe8QkESk J2xFc0R/mSQGZFVC+aLB/Y1qLciBWlHyjcxonvEWibs/7sQ2fOY7HiFfuCs2177AzOOHnX6U/c4+WJywm95l7Zj4MLjLssAB9KZEoYPAVOVWO7u4OEjyeKtQIcW0c+si/A85Qwc48kGLMoV8= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Oct 26, 2025 at 09:19:27PM +0000, Matthew Wilcox wrote: > it's quite different. I am by no stretch of the imagination a GFP > flags expert, but it seems to me that we should make the two the same > since they're both "try to allocate and we have a fallback if > necessary". I suspect kvmalloc() is called with a wider range of > GFP flags than bvec allocation is, so it's probably better tested. > > Is there a reason _not_ to use the kvmalloc code for bvec allocations? It's using a dedicated slab cache, which makes sense for such a frequent and usually short-lived allocation. We also don't use vmalloc backing ever at the moment.