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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 5E1A120015 X-Stat-Signature: w4bahjxg8ewr1bz5nqwqxyp9wnkhmr4g X-Rspam-User: X-HE-Tag: 1765858603-21877 X-HE-Meta: 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 6VDcBQCk FchnY0XGf2jvscp6pGU21X/o0p0qL7OWJi5et7KprmZrwm/1JrQkipsMMAe9VhMjHH7q8kI3e6JnMMkUfWMnY6pddzJCQSOrCBuzJaCR99o3arjvENzWvOQPDAcs6D8NdB3aM0vWzheznQN4hJcbBDE0DJVsZj87PBWJr2/aQokdFBfhRWwA0ajm405bTFEDaO2IdarT4yaluImuINXb10pWTikITM2Ouc7ZPl9A7UohGXsx6lv+10LK3EJYh8RbotsWUlDwvtI5YHBl8P3jPtqvOT3KBAtrZPPjR0IsNS5r+1Y0= 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 15/12/25 4:10 PM, Brendan Jackman wrote: > The only reason vmap_range_noflush() can sleep is because of pagetable > allocations. > > The actual allocation mechanism is arch-specific so might_alloc() > doesn't work here (what GFP flags would be used?). Hence, just add a > comment. > > Also note that this might do a TLB shootdown. This is not actually > sleeping but it requires IRQs on for x86, and might_sleep() incidentally > serves to detect violations of that too. > > Signed-off-by: Brendan Jackman Reviewed-by: Anshuman Khandual > --- > Applies to mm-new. > > Changes in v3: > - Added note about TLB shootdowns and x86. > - Since the comment no longer fit on one line anyway, also be a bit more > verbose in general. > - Link to v2: https://lore.kernel.org/r/20251209-b4-vmalloc-might_alloc-v2-1-2462ba26ead1@google.com > > Changes in v2: > - Switched from might_alloc() to keeping might_sleep() + comment > - Link to v1: https://lore.kernel.org/r/20251208-b4-vmalloc-might_alloc-v1-1-94a9bb8ecb08@google.com > --- > mm/vmalloc.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 41dd01e8430c548167d6123f6ec66bf798f20eec..be4e5f2566a4490d45de29568df538b7c8515b01 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -305,6 +305,11 @@ static int vmap_range_noflush(unsigned long addr, unsigned long end, > int err; > pgtbl_mod_mask mask = 0; > > + /* > + * Might allocate pagetables (for most archs a more precise annotation > + * would be might_alloc(GFP_PGTABLE_KERNEL)). Also might shootdown TLB > + * (requires IRQs enabled on x86). > + */ > might_sleep(); > BUG_ON(addr >= end); > > > --- > base-commit: d0a24447990a9d8212bfb3a692d59efa74ce9f86 > change-id: 20251208-b4-vmalloc-might_alloc-754a791e4e10 > > Best regards,