From mboxrd@z Thu Jan 1 00:00:00 1970 From: toshi.kani@hpe.com (Kani, Toshi) Date: Mon, 30 Apr 2018 13:43:37 +0000 Subject: [PATCH v2 2/2] x86/mm: implement free pmd/pte page interfaces In-Reply-To: References: <20180314180155.19492-1-toshi.kani@hpe.com> <20180314180155.19492-3-toshi.kani@hpe.com> <20180426141926.GN15462@8bytes.org> <1524759629.2693.465.camel@hpe.com> <20180426172327.GQ15462@8bytes.org> <1524764948.2693.478.camel@hpe.com> <20180426200737.GS15462@8bytes.org> <1524781764.2693.503.camel@hpe.com> <20180427073719.GT15462@8bytes.org> <1524839460.2693.531.camel@hpe.com> <20180428090217.n2l3w4vobmtkvz6k@8bytes.org> <1524948829.2693.547.camel@hpe.com> Message-ID: <1525095763.2693.550.camel@hpe.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 2018-04-30 at 13:00 +0530, Chintan Pandya wrote: > > On 4/29/2018 2:24 AM, Kani, Toshi wrote: > > On Sat, 2018-04-28 at 11:02 +0200, joro at 8bytes.org wrote: > > > On Fri, Apr 27, 2018 at 02:31:51PM +0000, Kani, Toshi wrote: > > > > So, we can add the step 2 on top of this patch. > > > > 1. Clear pud/pmd entry. > > > > 2. System wide TLB flush <-- TO BE ADDED BY NEW PATCH > > > > 3. Free its underlining pmd/pte page. > > > > > > This still lacks the page-table synchronization and will thus not fix > > > the BUG_ON being triggered. > > > > The BUG_ON issue is specific to PAE that it syncs at the pmd level. > > x86/64 does not have this issue since it syncs at the pgd or p4d level. > > > > > > We do not need to revert this patch. We can make the above change I > > > > mentioned. > > > > > > Please note that we are not in the merge window anymore and that any fix > > > needs to be simple and obviously correct. > > > > Understood. Changing the x86/32 sync point is risky. So, I am going to > > revert the free page handling for PAE. > > Will this affect pmd_free_pte_page() & pud_free_pmd_page() 's existence > or its parameters ? I'm asking because, I've similar change for arm64 > and ready to send v9 patches. No, it won't. The change is only to the x86 side. > I'm thinking to share my v9 patches in any case. If you are going to do > TLB invalidation within these APIs, my first patch will help. I will make my change on top of your v9 1/4 patch so that we can avoid merge conflict. Thanks, -Toshi