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Howlett" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rick Edgecombe Subject: Re: [PATCH v2] mm/mmap: Regression fix for unmapped_area{_topdown} Message-Id: <20230414120957.d69f471ad9eb2a1d304a4146@linux-foundation.org> In-Reply-To: <20230414185919.4175572-1-Liam.Howlett@oracle.com> References: <20230414145728.4067069-3-Liam.Howlett@oracle.com> <20230414185919.4175572-1-Liam.Howlett@oracle.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 Apr 2023 14:59:19 -0400 "Liam R. Howlett" wrote: > The maple tree limits the gap returned to a window that specifically > fits what was asked. This may not be optimal in the case of switching > search directions or a gap that does not satisfy the requested space for > other reasons. Fix the search by retrying the operation and limiting > the search window in the rare occasion that a conflict occurs. This is a performance regression, yes? Of what magnitude?