From mboxrd@z Thu Jan 1 00:00:00 1970 From: Davidlohr Bueso Subject: Re: [PATCH 2/6] lib/rhashtable: guarantee initial hashtable allocation Date: Tue, 29 May 2018 09:42:31 -0700 Message-ID: <20180529164231.yoj57nqhghtmy54v@linux-n805> References: <20180524211135.27760-1-dave@stgolabs.net> <20180524211135.27760-3-dave@stgolabs.net> <20180528100237.needq2u5e3v2n642@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <20180528100237.needq2u5e3v2n642@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org To: Herbert Xu Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, tgraf@suug.ch, manfred@colorfullife.com, guillaume.knispel@supersonicimagine.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Davidlohr Bueso List-Id: linux-api@vger.kernel.org On Mon, 28 May 2018, Herbert Xu wrote: >On Thu, May 24, 2018 at 02:11:31PM -0700, Davidlohr Bueso wrote: >> >> + /* >> + * This is api initialization and thus we need to guarantee the >> + * initial rhashtable allocation. Upon failure, retry with a >> + * smallest possible size, otherwise we exhaust our options with >> + * __GFP_NOFAIL. >> + */ >> tbl = bucket_table_alloc(ht, size, GFP_KERNEL); >> - if (tbl == NULL) >> - return -ENOMEM; >> + if (unlikely(tbl == NULL)) { >> + size = HASH_MIN_SIZE; > >You should also take min_size into account. Yes I know the current >code ignores it unless you also set nelem_hint. But that's just a >bug. For the sake of simplicity, Linus suggested directly using HASH_MIN_SIZE such that we have a single fallback. Thanks, Davidlohr